diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index 8527677ebb..5b18f37b6a 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -1344,7 +1344,7 @@ fn dumpSegfaultInfoPosix(sig: i32, code: i32, addr: usize, ctx_ptr: ?*anyopaque)
     }
 }
 
-fn handleSegfaultWindows(info: *windows.EXCEPTION_POINTERS) callconv(windows.WINAPI) c_long {
+fn handleSegfaultWindows(info: *windows.EXCEPTION_POINTERS) callconv(.winapi) c_long {
     switch (info.ExceptionRecord.ExceptionCode) {
         windows.EXCEPTION_DATATYPE_MISALIGNMENT => handleSegfaultWindowsExtra(info, 0, "Unaligned Memory Access"),
         windows.EXCEPTION_ACCESS_VIOLATION => handleSegfaultWindowsExtra(info, 1, null),
diff --git a/lib/std/os/windows.zig b/lib/std/os/windows.zig
index 6903bbf9a8..010bbcd005 100644
--- a/lib/std/os/windows.zig
+++ b/lib/std/os/windows.zig
@@ -2824,6 +2824,7 @@ pub const STD_OUTPUT_HANDLE = maxInt(DWORD) - 11 + 1;
 /// The standard error device. Initially, this is the active console screen buffer, CONOUT$.
 pub const STD_ERROR_HANDLE = maxInt(DWORD) - 12 + 1;
 
+/// Deprecated; use `std.builtin.CallingConvention.winapi` instead.
 pub const WINAPI: std.builtin.CallingConvention = .winapi;
 
 pub const BOOL = c_int;
diff --git a/lib/std/os/windows/advapi32.zig b/lib/std/os/windows/advapi32.zig
index 3419fdc95c..bf438e2776 100644
--- a/lib/std/os/windows/advapi32.zig
+++ b/lib/std/os/windows/advapi32.zig
@@ -8,7 +8,6 @@ const LPCWSTR = windows.LPCWSTR;
 const LSTATUS = windows.LSTATUS;
 const REGSAM = windows.REGSAM;
 const ULONG = windows.ULONG;
-const WINAPI = windows.WINAPI;
 
 pub extern "advapi32" fn RegOpenKeyExW(
     hKey: HKEY,
@@ -16,7 +15,7 @@ pub extern "advapi32" fn RegOpenKeyExW(
     ulOptions: DWORD,
     samDesired: REGSAM,
     phkResult: *HKEY,
-) callconv(WINAPI) LSTATUS;
+) callconv(.winapi) LSTATUS;
 
 pub extern "advapi32" fn RegQueryValueExW(
     hKey: HKEY,
@@ -25,13 +24,13 @@ pub extern "advapi32" fn RegQueryValueExW(
     lpType: ?*DWORD,
     lpData: ?*BYTE,
     lpcbData: ?*DWORD,
-) callconv(WINAPI) LSTATUS;
+) callconv(.winapi) LSTATUS;
 
-pub extern "advapi32" fn RegCloseKey(hKey: HKEY) callconv(WINAPI) LSTATUS;
+pub extern "advapi32" fn RegCloseKey(hKey: HKEY) callconv(.winapi) LSTATUS;
 
 // RtlGenRandom is known as SystemFunction036 under advapi32
 // http://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx */
-pub extern "advapi32" fn SystemFunction036(output: [*]u8, length: ULONG) callconv(WINAPI) BOOL;
+pub extern "advapi32" fn SystemFunction036(output: [*]u8, length: ULONG) callconv(.winapi) BOOL;
 pub const RtlGenRandom = SystemFunction036;
 
 pub const RRF = struct {
@@ -62,7 +61,7 @@ pub extern "advapi32" fn RegGetValueW(
     pdwType: ?*DWORD,
     pvData: ?*anyopaque,
     pcbData: ?*DWORD,
-) callconv(WINAPI) LSTATUS;
+) callconv(.winapi) LSTATUS;
 
 pub extern "advapi32" fn RegLoadAppKeyW(
     lpFile: LPCWSTR,
@@ -70,4 +69,4 @@ pub extern "advapi32" fn RegLoadAppKeyW(
     samDesired: REGSAM,
     dwOptions: DWORD,
     reserved: DWORD,
-) callconv(WINAPI) LSTATUS;
+) callconv(.winapi) LSTATUS;
diff --git a/lib/std/os/windows/crypt32.zig b/lib/std/os/windows/crypt32.zig
index 9500d4b261..37d8110405 100644
--- a/lib/std/os/windows/crypt32.zig
+++ b/lib/std/os/windows/crypt32.zig
@@ -4,7 +4,6 @@ const BOOL = windows.BOOL;
 const DWORD = windows.DWORD;
 const BYTE = windows.BYTE;
 const LPCWSTR = windows.LPCWSTR;
-const WINAPI = windows.WINAPI;
 
 pub const CERT_INFO = *opaque {};
 pub const HCERTSTORE = *opaque {};
@@ -19,14 +18,14 @@ pub const CERT_CONTEXT = extern struct {
 pub extern "crypt32" fn CertOpenSystemStoreW(
     _: ?*const anyopaque,
     szSubsystemProtocol: LPCWSTR,
-) callconv(WINAPI) ?HCERTSTORE;
+) callconv(.winapi) ?HCERTSTORE;
 
 pub extern "crypt32" fn CertCloseStore(
     hCertStore: HCERTSTORE,
     dwFlags: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "crypt32" fn CertEnumCertificatesInStore(
     hCertStore: HCERTSTORE,
     pPrevCertContext: ?*CERT_CONTEXT,
-) callconv(WINAPI) ?*CERT_CONTEXT;
+) callconv(.winapi) ?*CERT_CONTEXT;
diff --git a/lib/std/os/windows/kernel32.zig b/lib/std/os/windows/kernel32.zig
index b8ae72af55..f2da7957a8 100644
--- a/lib/std/os/windows/kernel32.zig
+++ b/lib/std/os/windows/kernel32.zig
@@ -41,7 +41,6 @@ const VECTORED_EXCEPTION_HANDLER = windows.VECTORED_EXCEPTION_HANDLER;
 const WCHAR = windows.WCHAR;
 const WIN32_FIND_DATAW = windows.WIN32_FIND_DATAW;
 const Win32Error = windows.Win32Error;
-const WINAPI = windows.WINAPI;
 const WORD = windows.WORD;
 
 // I/O - Filesystem
@@ -55,18 +54,18 @@ pub extern "kernel32" fn ReadDirectoryChangesW(
     lpBytesReturned: ?*windows.DWORD,
     lpOverlapped: ?*windows.OVERLAPPED,
     lpCompletionRoutine: windows.LPOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(windows.WINAPI) windows.BOOL;
+) callconv(.winapi) windows.BOOL;
 
 // TODO: Wrapper around NtCancelIoFile.
 pub extern "kernel32" fn CancelIo(
     hFile: HANDLE,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtCancelIoFileEx.
 pub extern "kernel32" fn CancelIoEx(
     hFile: HANDLE,
     lpOverlapped: ?*OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn CreateFileW(
     lpFileName: LPCWSTR,
@@ -76,7 +75,7 @@ pub extern "kernel32" fn CreateFileW(
     dwCreationDisposition: DWORD,
     dwFlagsAndAttributes: DWORD,
     hTemplateFile: ?HANDLE,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 // TODO A bunch of logic around NtCreateNamedPipe
 pub extern "kernel32" fn CreateNamedPipeW(
@@ -88,16 +87,16 @@ pub extern "kernel32" fn CreateNamedPipeW(
     nInBufferSize: DWORD,
     nDefaultTimeOut: DWORD,
     lpSecurityAttributes: ?*const SECURITY_ATTRIBUTES,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 pub extern "kernel32" fn FindFirstFileW(
     lpFileName: LPCWSTR,
     lpFindFileData: *WIN32_FIND_DATAW,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 pub extern "kernel32" fn FindClose(
     hFindFile: HANDLE,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around RtlGetFullPathName_UEx
 pub extern "kernel32" fn GetFullPathNameW(
@@ -105,18 +104,18 @@ pub extern "kernel32" fn GetFullPathNameW(
     nBufferLength: DWORD,
     lpBuffer: LPWSTR,
     lpFilePart: ?*?LPWSTR,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: Matches `STD_*_HANDLE` to peb().ProcessParameters.Standard*
 pub extern "kernel32" fn GetStdHandle(
     nStdHandle: DWORD,
-) callconv(WINAPI) ?HANDLE;
+) callconv(.winapi) ?HANDLE;
 
 pub extern "kernel32" fn MoveFileExW(
     lpExistingFileName: LPCWSTR,
     lpNewFileName: LPCWSTR,
     dwFlags: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtSetInformationFile + `FILE_POSITION_INFORMATION`.
 //  `FILE_STANDARD_INFORMATION` is also used if dwMoveMethod is `FILE_END`
@@ -125,7 +124,7 @@ pub extern "kernel32" fn SetFilePointerEx(
     liDistanceToMove: LARGE_INTEGER,
     lpNewFilePointer: ?*LARGE_INTEGER,
     dwMoveMethod: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtSetInformationFile + `FILE_BASIC_INFORMATION`
 pub extern "kernel32" fn SetFileTime(
@@ -133,7 +132,7 @@ pub extern "kernel32" fn SetFileTime(
     lpCreationTime: ?*const FILETIME,
     lpLastAccessTime: ?*const FILETIME,
     lpLastWriteTime: ?*const FILETIME,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn WriteFile(
     in_hFile: HANDLE,
@@ -141,35 +140,35 @@ pub extern "kernel32" fn WriteFile(
     in_nNumberOfBytesToWrite: DWORD,
     out_lpNumberOfBytesWritten: ?*DWORD,
     in_out_lpOverlapped: ?*OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: wrapper for NtQueryInformationFile + `FILE_STANDARD_INFORMATION`
 pub extern "kernel32" fn GetFileSizeEx(
     hFile: HANDLE,
     lpFileSize: *LARGE_INTEGER,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around GetStdHandle + NtFlushBuffersFile.
 pub extern "kernel32" fn FlushFileBuffers(
     hFile: HANDLE,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtSetInformationFile + `FILE_IO_COMPLETION_NOTIFICATION_INFORMATION`.
 pub extern "kernel32" fn SetFileCompletionNotificationModes(
     FileHandle: HANDLE,
     Flags: UCHAR,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: `RtlGetCurrentDirectory_U(nBufferLength * 2, lpBuffer)`
 pub extern "kernel32" fn GetCurrentDirectoryW(
     nBufferLength: DWORD,
     lpBuffer: ?[*]WCHAR,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: RtlDosPathNameToNtPathNameU_WithStatus + NtQueryAttributesFile.
 pub extern "kernel32" fn GetFileAttributesW(
     lpFileName: LPCWSTR,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 pub extern "kernel32" fn ReadFile(
     hFile: HANDLE,
@@ -177,12 +176,12 @@ pub extern "kernel32" fn ReadFile(
     nNumberOfBytesToRead: DWORD,
     lpNumberOfBytesRead: ?*DWORD,
     lpOverlapped: ?*OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn GetSystemDirectoryW(
     lpBuffer: LPWSTR,
     uSize: UINT,
-) callconv(WINAPI) UINT;
+) callconv(.winapi) UINT;
 
 // I/O - Kernel Objects
 
@@ -192,7 +191,7 @@ pub extern "kernel32" fn CreateEventExW(
     lpName: ?LPCWSTR,
     dwFlags: DWORD,
     dwDesiredAccess: DWORD,
-) callconv(WINAPI) ?HANDLE;
+) callconv(.winapi) ?HANDLE;
 
 // TODO: Wrapper around GetStdHandle + NtDuplicateObject.
 pub extern "kernel32" fn DuplicateHandle(
@@ -203,14 +202,14 @@ pub extern "kernel32" fn DuplicateHandle(
     dwDesiredAccess: DWORD,
     bInheritHandle: BOOL,
     dwOptions: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around GetStdHandle + NtQueryObject + NtSetInformationObject with .ObjectHandleFlagInformation.
 pub extern "kernel32" fn SetHandleInformation(
     hObject: HANDLE,
     dwMask: DWORD,
     dwFlags: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtRemoveIoCompletion.
 pub extern "kernel32" fn GetQueuedCompletionStatus(
@@ -219,7 +218,7 @@ pub extern "kernel32" fn GetQueuedCompletionStatus(
     lpCompletionKey: *ULONG_PTR,
     lpOverlapped: *?*OVERLAPPED,
     dwMilliseconds: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtRemoveIoCompletionEx.
 pub extern "kernel32" fn GetQueuedCompletionStatusEx(
@@ -229,7 +228,7 @@ pub extern "kernel32" fn GetQueuedCompletionStatusEx(
     ulNumEntriesRemoved: *ULONG,
     dwMilliseconds: DWORD,
     fAlertable: BOOL,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtSetIoCompletion with `IoStatus = .SUCCESS`.
 pub extern "kernel32" fn PostQueuedCompletionStatus(
@@ -237,7 +236,7 @@ pub extern "kernel32" fn PostQueuedCompletionStatus(
     dwNumberOfBytesTransferred: DWORD,
     dwCompletionKey: ULONG_PTR,
     lpOverlapped: ?*OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO:
 // GetOverlappedResultEx with bAlertable=false, which calls: GetStdHandle + WaitForSingleObjectEx.
@@ -247,7 +246,7 @@ pub extern "kernel32" fn GetOverlappedResult(
     lpOverlapped: *OVERLAPPED,
     lpNumberOfBytesTransferred: *DWORD,
     bWait: BOOL,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtCreateIoCompletion + NtSetInformationFile with FILE_COMPLETION_INFORMATION.
 // This would be better splitting into two functions.
@@ -256,30 +255,30 @@ pub extern "kernel32" fn CreateIoCompletionPort(
     ExistingCompletionPort: ?HANDLE,
     CompletionKey: ULONG_PTR,
     NumberOfConcurrentThreads: DWORD,
-) callconv(WINAPI) ?HANDLE;
+) callconv(.winapi) ?HANDLE;
 
 // TODO: Forwarder to NtAddVectoredExceptionHandler.
 pub extern "kernel32" fn AddVectoredExceptionHandler(
     First: ULONG,
     Handler: ?VECTORED_EXCEPTION_HANDLER,
-) callconv(WINAPI) ?LPVOID;
+) callconv(.winapi) ?LPVOID;
 
 // TODO: Forwarder to NtRemoveVectoredExceptionHandler.
 pub extern "kernel32" fn RemoveVectoredExceptionHandler(
     Handle: HANDLE,
-) callconv(WINAPI) ULONG;
+) callconv(.winapi) ULONG;
 
 // TODO: Wrapper around RtlReportSilentProcessExit + NtTerminateProcess.
 pub extern "kernel32" fn TerminateProcess(
     hProcess: HANDLE,
     uExitCode: UINT,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: WaitForSingleObjectEx with bAlertable=false.
 pub extern "kernel32" fn WaitForSingleObject(
     hHandle: HANDLE,
     dwMilliseconds: DWORD,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: Wrapper for GetStdHandle + NtWaitForSingleObject.
 // Sets up an activation context before calling NtWaitForSingleObject.
@@ -287,7 +286,7 @@ pub extern "kernel32" fn WaitForSingleObjectEx(
     hHandle: HANDLE,
     dwMilliseconds: DWORD,
     bAlertable: BOOL,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: WaitForMultipleObjectsEx with alertable=false
 pub extern "kernel32" fn WaitForMultipleObjects(
@@ -295,7 +294,7 @@ pub extern "kernel32" fn WaitForMultipleObjects(
     lpHandle: [*]const HANDLE,
     bWaitAll: BOOL,
     dwMilliseconds: DWORD,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: Wrapper around NtWaitForMultipleObjects.
 pub extern "kernel32" fn WaitForMultipleObjectsEx(
@@ -304,7 +303,7 @@ pub extern "kernel32" fn WaitForMultipleObjectsEx(
     bWaitAll: BOOL,
     dwMilliseconds: DWORD,
     bAlertable: BOOL,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // Process Management
 
@@ -319,57 +318,57 @@ pub extern "kernel32" fn CreateProcessW(
     lpCurrentDirectory: ?LPCWSTR,
     lpStartupInfo: *STARTUPINFOW,
     lpProcessInformation: *PROCESS_INFORMATION,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Fowarder to RtlExitUserProcess.
 pub extern "kernel32" fn ExitProcess(
     exit_code: UINT,
-) callconv(WINAPI) noreturn;
+) callconv(.winapi) noreturn;
 
 // TODO: SleepEx with bAlertable=false.
 pub extern "kernel32" fn Sleep(
     dwMilliseconds: DWORD,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Wrapper around NtQueryInformationProcess with `PROCESS_BASIC_INFORMATION`.
 pub extern "kernel32" fn GetExitCodeProcess(
     hProcess: HANDLE,
     lpExitCode: *DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Already a wrapper for this, see `windows.GetCurrentProcess`.
-pub extern "kernel32" fn GetCurrentProcess() callconv(WINAPI) HANDLE;
+pub extern "kernel32" fn GetCurrentProcess() callconv(.winapi) HANDLE;
 
 // TODO: memcpy peb().ProcessParameters.Environment, mem.span(0). Requires locking the PEB.
-pub extern "kernel32" fn GetEnvironmentStringsW() callconv(WINAPI) ?LPWSTR;
+pub extern "kernel32" fn GetEnvironmentStringsW() callconv(.winapi) ?LPWSTR;
 
 // TODO: RtlFreeHeap on the output of GetEnvironmentStringsW.
 pub extern "kernel32" fn FreeEnvironmentStringsW(
     penv: LPWSTR,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around RtlQueryEnvironmentVariable.
 pub extern "kernel32" fn GetEnvironmentVariableW(
     lpName: ?LPCWSTR,
     lpBuffer: ?[*]WCHAR,
     nSize: DWORD,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: Wrapper around RtlSetEnvironmentVar.
 pub extern "kernel32" fn SetEnvironmentVariableW(
     lpName: LPCWSTR,
     lpValue: ?LPCWSTR,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn CreateToolhelp32Snapshot(
     dwFlags: DWORD,
     th32ProcessID: DWORD,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 // Threading
 
 // TODO: Already a wrapper for this, see `windows.GetCurrentThreadId`.
-pub extern "kernel32" fn GetCurrentThreadId() callconv(WINAPI) DWORD;
+pub extern "kernel32" fn GetCurrentThreadId() callconv(.winapi) DWORD;
 
 // TODO: CreateRemoteThread with hProcess=NtCurrentProcess().
 pub extern "kernel32" fn CreateThread(
@@ -379,64 +378,64 @@ pub extern "kernel32" fn CreateThread(
     lpParameter: ?LPVOID,
     dwCreationFlags: DWORD,
     lpThreadId: ?*DWORD,
-) callconv(WINAPI) ?HANDLE;
+) callconv(.winapi) ?HANDLE;
 
 // TODO: Wrapper around RtlDelayExecution.
-pub extern "kernel32" fn SwitchToThread() callconv(WINAPI) BOOL;
+pub extern "kernel32" fn SwitchToThread() callconv(.winapi) BOOL;
 
 // Locks, critical sections, initializers
 
 // TODO: Forwarder to RtlInitializeCriticalSection
 pub extern "kernel32" fn InitializeCriticalSection(
     lpCriticalSection: *CRITICAL_SECTION,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Forwarder to RtlEnterCriticalSection
 pub extern "kernel32" fn EnterCriticalSection(
     lpCriticalSection: *CRITICAL_SECTION,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Forwarder to RtlLeaveCriticalSection
 pub extern "kernel32" fn LeaveCriticalSection(
     lpCriticalSection: *CRITICAL_SECTION,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Forwarder to RtlDeleteCriticalSection
 pub extern "kernel32" fn DeleteCriticalSection(
     lpCriticalSection: *CRITICAL_SECTION,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Forwarder to RtlTryAcquireSRWLockExclusive
 pub extern "kernel32" fn TryAcquireSRWLockExclusive(
     SRWLock: *SRWLOCK,
-) callconv(WINAPI) BOOLEAN;
+) callconv(.winapi) BOOLEAN;
 
 // TODO: Forwarder to RtlAcquireSRWLockExclusive
 pub extern "kernel32" fn AcquireSRWLockExclusive(
     SRWLock: *SRWLOCK,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Forwarder to RtlReleaseSRWLockExclusive
 pub extern "kernel32" fn ReleaseSRWLockExclusive(
     SRWLock: *SRWLOCK,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub extern "kernel32" fn InitOnceExecuteOnce(
     InitOnce: *INIT_ONCE,
     InitFn: INIT_ONCE_FN,
     Parameter: ?*anyopaque,
     Context: ?*anyopaque,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Forwarder to RtlWakeConditionVariable
 pub extern "kernel32" fn WakeConditionVariable(
     ConditionVariable: *CONDITION_VARIABLE,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO: Forwarder to RtlWakeAllConditionVariable
 pub extern "kernel32" fn WakeAllConditionVariable(
     ConditionVariable: *CONDITION_VARIABLE,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // TODO:
 //  - dwMilliseconds -> LARGE_INTEGER.
@@ -447,40 +446,40 @@ pub extern "kernel32" fn SleepConditionVariableSRW(
     SRWLock: *SRWLOCK,
     dwMilliseconds: DWORD,
     Flags: ULONG,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // Console management
 
 pub extern "kernel32" fn GetConsoleMode(
     hConsoleHandle: HANDLE,
     lpMode: *DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn SetConsoleMode(
     hConsoleHandle: HANDLE,
     dwMode: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn GetConsoleScreenBufferInfo(
     hConsoleOutput: HANDLE,
     lpConsoleScreenBufferInfo: *CONSOLE_SCREEN_BUFFER_INFO,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn SetConsoleTextAttribute(
     hConsoleOutput: HANDLE,
     wAttributes: WORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn SetConsoleCtrlHandler(
     HandlerRoutine: ?HANDLER_ROUTINE,
     Add: BOOL,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn SetConsoleOutputCP(
     wCodePageID: UINT,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
-pub extern "kernel32" fn GetConsoleOutputCP() callconv(WINAPI) UINT;
+pub extern "kernel32" fn GetConsoleOutputCP() callconv(.winapi) UINT;
 
 pub extern "kernel32" fn FillConsoleOutputAttribute(
     hConsoleOutput: HANDLE,
@@ -488,7 +487,7 @@ pub extern "kernel32" fn FillConsoleOutputAttribute(
     nLength: DWORD,
     dwWriteCoord: COORD,
     lpNumberOfAttrsWritten: *DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn FillConsoleOutputCharacterW(
     hConsoleOutput: HANDLE,
@@ -496,12 +495,12 @@ pub extern "kernel32" fn FillConsoleOutputCharacterW(
     nLength: DWORD,
     dwWriteCoord: COORD,
     lpNumberOfCharsWritten: *DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn SetConsoleCursorPosition(
     hConsoleOutput: HANDLE,
     dwCursorPosition: COORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn WriteConsoleW(
     hConsoleOutput: HANDLE,
@@ -509,7 +508,7 @@ pub extern "kernel32" fn WriteConsoleW(
     nNumberOfCharsToWrite: DWORD,
     lpNumberOfCharsWritten: ?*DWORD,
     lpReserved: ?LPVOID,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn ReadConsoleOutputCharacterW(
     hConsoleOutput: HANDLE,
@@ -517,7 +516,7 @@ pub extern "kernel32" fn ReadConsoleOutputCharacterW(
     nLength: DWORD,
     dwReadCoord: COORD,
     lpNumberOfCharsRead: *DWORD,
-) callconv(windows.WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // Memory Mapping/Allocation
 
@@ -526,12 +525,12 @@ pub extern "kernel32" fn HeapCreate(
     flOptions: DWORD,
     dwInitialSize: SIZE_T,
     dwMaximumSize: SIZE_T,
-) callconv(WINAPI) ?HANDLE;
+) callconv(.winapi) ?HANDLE;
 
 // TODO: Wrapper around RtlDestroyHeap (BOOLEAN -> BOOL).
 pub extern "kernel32" fn HeapDestroy(
     hHeap: HANDLE,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Forwarder to RtlReAllocateHeap.
 pub extern "kernel32" fn HeapReAlloc(
@@ -539,28 +538,28 @@ pub extern "kernel32" fn HeapReAlloc(
     dwFlags: DWORD,
     lpMem: *anyopaque,
     dwBytes: SIZE_T,
-) callconv(WINAPI) ?*anyopaque;
+) callconv(.winapi) ?*anyopaque;
 
 // TODO: Fowrarder to RtlAllocateHeap.
 pub extern "kernel32" fn HeapAlloc(
     hHeap: HANDLE,
     dwFlags: DWORD,
     dwBytes: SIZE_T,
-) callconv(WINAPI) ?*anyopaque;
+) callconv(.winapi) ?*anyopaque;
 
 // TODO: Fowrarder to RtlFreeHeap.
 pub extern "kernel32" fn HeapFree(
     hHeap: HANDLE,
     dwFlags: DWORD,
     lpMem: LPVOID,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around RtlValidateHeap (BOOLEAN -> BOOL)
 pub extern "kernel32" fn HeapValidate(
     hHeap: HANDLE,
     dwFlags: DWORD,
     lpMem: ?*const anyopaque,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtAllocateVirtualMemory.
 pub extern "kernel32" fn VirtualAlloc(
@@ -568,7 +567,7 @@ pub extern "kernel32" fn VirtualAlloc(
     dwSize: SIZE_T,
     flAllocationType: DWORD,
     flProtect: DWORD,
-) callconv(WINAPI) ?LPVOID;
+) callconv(.winapi) ?LPVOID;
 
 // TODO: Wrapper around NtFreeVirtualMemory.
 // If the return value is .INVALID_PAGE_PROTECTION, calls RtlFlushSecureMemoryCache and try again.
@@ -576,21 +575,21 @@ pub extern "kernel32" fn VirtualFree(
     lpAddress: ?LPVOID,
     dwSize: SIZE_T,
     dwFreeType: DWORD,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // TODO: Wrapper around NtQueryVirtualMemory.
 pub extern "kernel32" fn VirtualQuery(
     lpAddress: ?LPVOID,
     lpBuffer: PMEMORY_BASIC_INFORMATION,
     dwLength: SIZE_T,
-) callconv(WINAPI) SIZE_T;
+) callconv(.winapi) SIZE_T;
 
 pub extern "kernel32" fn LocalFree(
     hMem: HLOCAL,
-) callconv(WINAPI) ?HLOCAL;
+) callconv(.winapi) ?HLOCAL;
 
 // TODO: Getter for peb.ProcessHeap
-pub extern "kernel32" fn GetProcessHeap() callconv(WINAPI) ?HANDLE;
+pub extern "kernel32" fn GetProcessHeap() callconv(.winapi) ?HANDLE;
 
 // Code Libraries/Modules
 
@@ -599,49 +598,49 @@ pub extern "kernel32" fn GetModuleFileNameW(
     hModule: ?HMODULE,
     lpFilename: [*]WCHAR,
     nSize: DWORD,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 extern "kernel32" fn K32GetModuleFileNameExW(
     hProcess: HANDLE,
     hModule: ?HMODULE,
     lpFilename: LPWSTR,
     nSize: DWORD,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 pub const GetModuleFileNameExW = K32GetModuleFileNameExW;
 
 // TODO: Wrapper around ntdll.LdrGetDllHandle, which is a wrapper around LdrGetDllHandleEx
 pub extern "kernel32" fn GetModuleHandleW(
     lpModuleName: ?LPCWSTR,
-) callconv(WINAPI) ?HMODULE;
+) callconv(.winapi) ?HMODULE;
 
 pub extern "kernel32" fn Module32First(
     hSnapshot: HANDLE,
     lpme: *MODULEENTRY32,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn Module32Next(
     hSnapshot: HANDLE,
     lpme: *MODULEENTRY32,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "kernel32" fn LoadLibraryW(
     lpLibFileName: LPCWSTR,
-) callconv(WINAPI) ?HMODULE;
+) callconv(.winapi) ?HMODULE;
 
 pub extern "kernel32" fn LoadLibraryExW(
     lpLibFileName: LPCWSTR,
     hFile: ?HANDLE,
     dwFlags: DWORD,
-) callconv(WINAPI) ?HMODULE;
+) callconv(.winapi) ?HMODULE;
 
 pub extern "kernel32" fn GetProcAddress(
     hModule: HMODULE,
     lpProcName: LPCSTR,
-) callconv(WINAPI) ?FARPROC;
+) callconv(.winapi) ?FARPROC;
 
 pub extern "kernel32" fn FreeLibrary(
     hModule: HMODULE,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 // Error Management
 
@@ -653,15 +652,15 @@ pub extern "kernel32" fn FormatMessageW(
     lpBuffer: LPWSTR,
     nSize: DWORD,
     Arguments: ?*va_list,
-) callconv(WINAPI) DWORD;
+) callconv(.winapi) DWORD;
 
 // TODO: Getter for teb().LastErrorValue.
-pub extern "kernel32" fn GetLastError() callconv(WINAPI) Win32Error;
+pub extern "kernel32" fn GetLastError() callconv(.winapi) Win32Error;
 
 // TODO: Wrapper around RtlSetLastWin32Error.
 pub extern "kernel32" fn SetLastError(
     dwErrCode: Win32Error,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 // Everything Else
 
@@ -670,4 +669,4 @@ pub extern "kernel32" fn SetLastError(
 //  Much better to use NtQuerySystemTime or NtQuerySystemTimePrecise for guaranteed 0.1ns precision.
 pub extern "kernel32" fn GetSystemTimeAsFileTime(
     lpSystemTimeAsFileTime: *FILETIME,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
diff --git a/lib/std/os/windows/ntdll.zig b/lib/std/os/windows/ntdll.zig
index 4683b1e887..b4c33a2e2d 100644
--- a/lib/std/os/windows/ntdll.zig
+++ b/lib/std/os/windows/ntdll.zig
@@ -5,7 +5,6 @@ const BOOL = windows.BOOL;
 const DWORD = windows.DWORD;
 const DWORD64 = windows.DWORD64;
 const ULONG = windows.ULONG;
-const WINAPI = windows.WINAPI;
 const NTSTATUS = windows.NTSTATUS;
 const WORD = windows.WORD;
 const HANDLE = windows.HANDLE;
@@ -44,7 +43,7 @@ pub extern "ntdll" fn NtQueryInformationProcess(
     ProcessInformation: *anyopaque,
     ProcessInformationLength: ULONG,
     ReturnLength: ?*ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtQueryInformationThread(
     ThreadHandle: HANDLE,
@@ -52,37 +51,37 @@ pub extern "ntdll" fn NtQueryInformationThread(
     ThreadInformation: *anyopaque,
     ThreadInformationLength: ULONG,
     ReturnLength: ?*ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtQuerySystemInformation(
     SystemInformationClass: SYSTEM_INFORMATION_CLASS,
     SystemInformation: PVOID,
     SystemInformationLength: ULONG,
     ReturnLength: ?*ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtSetInformationThread(
     ThreadHandle: HANDLE,
     ThreadInformationClass: THREADINFOCLASS,
     ThreadInformation: *const anyopaque,
     ThreadInformationLength: ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn RtlGetVersion(
     lpVersionInformation: *RTL_OSVERSIONINFOW,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn RtlCaptureStackBackTrace(
     FramesToSkip: DWORD,
     FramesToCapture: DWORD,
     BackTrace: **anyopaque,
     BackTraceHash: ?*DWORD,
-) callconv(WINAPI) WORD;
-pub extern "ntdll" fn RtlCaptureContext(ContextRecord: *CONTEXT) callconv(WINAPI) void;
+) callconv(.winapi) WORD;
+pub extern "ntdll" fn RtlCaptureContext(ContextRecord: *CONTEXT) callconv(.winapi) void;
 pub extern "ntdll" fn RtlLookupFunctionEntry(
     ControlPc: DWORD64,
     ImageBase: *DWORD64,
     HistoryTable: *UNWIND_HISTORY_TABLE,
-) callconv(WINAPI) ?*RUNTIME_FUNCTION;
+) callconv(.winapi) ?*RUNTIME_FUNCTION;
 pub extern "ntdll" fn RtlVirtualUnwind(
     HandlerType: DWORD,
     ImageBase: DWORD64,
@@ -92,33 +91,33 @@ pub extern "ntdll" fn RtlVirtualUnwind(
     HandlerData: *?PVOID,
     EstablisherFrame: *DWORD64,
     ContextPointers: ?*KNONVOLATILE_CONTEXT_POINTERS,
-) callconv(WINAPI) *EXCEPTION_ROUTINE;
+) callconv(.winapi) *EXCEPTION_ROUTINE;
 pub extern "ntdll" fn NtQueryInformationFile(
     FileHandle: HANDLE,
     IoStatusBlock: *IO_STATUS_BLOCK,
     FileInformation: *anyopaque,
     Length: ULONG,
     FileInformationClass: FILE_INFORMATION_CLASS,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn NtSetInformationFile(
     FileHandle: HANDLE,
     IoStatusBlock: *IO_STATUS_BLOCK,
     FileInformation: PVOID,
     Length: ULONG,
     FileInformationClass: FILE_INFORMATION_CLASS,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtQueryAttributesFile(
     ObjectAttributes: *OBJECT_ATTRIBUTES,
     FileAttributes: *FILE_BASIC_INFORMATION,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
-pub extern "ntdll" fn RtlQueryPerformanceCounter(PerformanceCounter: *LARGE_INTEGER) callconv(WINAPI) BOOL;
-pub extern "ntdll" fn RtlQueryPerformanceFrequency(PerformanceFrequency: *LARGE_INTEGER) callconv(WINAPI) BOOL;
+pub extern "ntdll" fn RtlQueryPerformanceCounter(PerformanceCounter: *LARGE_INTEGER) callconv(.winapi) BOOL;
+pub extern "ntdll" fn RtlQueryPerformanceFrequency(PerformanceFrequency: *LARGE_INTEGER) callconv(.winapi) BOOL;
 pub extern "ntdll" fn NtQueryPerformanceCounter(
     PerformanceCounter: *LARGE_INTEGER,
     PerformanceFrequency: ?*LARGE_INTEGER,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtCreateFile(
     FileHandle: *HANDLE,
@@ -132,7 +131,7 @@ pub extern "ntdll" fn NtCreateFile(
     CreateOptions: ULONG,
     EaBuffer: ?*anyopaque,
     EaLength: ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn NtCreateSection(
     SectionHandle: *HANDLE,
     DesiredAccess: ACCESS_MASK,
@@ -141,7 +140,7 @@ pub extern "ntdll" fn NtCreateSection(
     SectionPageProtection: ULONG,
     AllocationAttributes: ULONG,
     FileHandle: ?HANDLE,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn NtMapViewOfSection(
     SectionHandle: HANDLE,
     ProcessHandle: HANDLE,
@@ -153,11 +152,11 @@ pub extern "ntdll" fn NtMapViewOfSection(
     InheritDispostion: SECTION_INHERIT,
     AllocationType: ULONG,
     Win32Protect: ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn NtUnmapViewOfSection(
     ProcessHandle: HANDLE,
     BaseAddress: PVOID,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn NtDeviceIoControlFile(
     FileHandle: HANDLE,
     Event: ?HANDLE,
@@ -169,7 +168,7 @@ pub extern "ntdll" fn NtDeviceIoControlFile(
     InputBufferLength: ULONG,
     OutputBuffer: ?PVOID,
     OutputBufferLength: ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn NtFsControlFile(
     FileHandle: HANDLE,
     Event: ?HANDLE,
@@ -181,15 +180,15 @@ pub extern "ntdll" fn NtFsControlFile(
     InputBufferLength: ULONG,
     OutputBuffer: ?PVOID,
     OutputBufferLength: ULONG,
-) callconv(WINAPI) NTSTATUS;
-pub extern "ntdll" fn NtClose(Handle: HANDLE) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
+pub extern "ntdll" fn NtClose(Handle: HANDLE) callconv(.winapi) NTSTATUS;
 pub extern "ntdll" fn RtlDosPathNameToNtPathName_U(
     DosPathName: [*:0]const u16,
     NtPathName: *UNICODE_STRING,
     NtFileNamePart: ?*?[*:0]const u16,
     DirectoryInfo: ?*CURDIR,
-) callconv(WINAPI) BOOL;
-pub extern "ntdll" fn RtlFreeUnicodeString(UnicodeString: *UNICODE_STRING) callconv(WINAPI) void;
+) callconv(.winapi) BOOL;
+pub extern "ntdll" fn RtlFreeUnicodeString(UnicodeString: *UNICODE_STRING) callconv(.winapi) void;
 
 /// Returns the number of bytes written to `Buffer`.
 /// If the returned count is larger than `BufferByteLength`, the buffer was too small.
@@ -199,7 +198,7 @@ pub extern "ntdll" fn RtlGetFullPathName_U(
     BufferByteLength: ULONG,
     Buffer: [*]u16,
     ShortName: ?*[*:0]const u16,
-) callconv(windows.WINAPI) windows.ULONG;
+) callconv(.winapi) windows.ULONG;
 
 pub extern "ntdll" fn NtQueryDirectoryFile(
     FileHandle: HANDLE,
@@ -213,30 +212,30 @@ pub extern "ntdll" fn NtQueryDirectoryFile(
     ReturnSingleEntry: BOOLEAN,
     FileName: ?*UNICODE_STRING,
     RestartScan: BOOLEAN,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtCreateKeyedEvent(
     KeyedEventHandle: *HANDLE,
     DesiredAccess: ACCESS_MASK,
     ObjectAttributes: ?PVOID,
     Flags: ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtReleaseKeyedEvent(
     EventHandle: ?HANDLE,
     Key: ?*const anyopaque,
     Alertable: BOOLEAN,
     Timeout: ?*const LARGE_INTEGER,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtWaitForKeyedEvent(
     EventHandle: ?HANDLE,
     Key: ?*const anyopaque,
     Alertable: BOOLEAN,
     Timeout: ?*const LARGE_INTEGER,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
-pub extern "ntdll" fn RtlSetCurrentDirectory_U(PathName: *UNICODE_STRING) callconv(WINAPI) NTSTATUS;
+pub extern "ntdll" fn RtlSetCurrentDirectory_U(PathName: *UNICODE_STRING) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtQueryObject(
     Handle: HANDLE,
@@ -244,7 +243,7 @@ pub extern "ntdll" fn NtQueryObject(
     ObjectInformation: PVOID,
     ObjectInformationLength: ULONG,
     ReturnLength: ?*ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtQueryVolumeInformationFile(
     FileHandle: HANDLE,
@@ -252,32 +251,32 @@ pub extern "ntdll" fn NtQueryVolumeInformationFile(
     FsInformation: *anyopaque,
     Length: ULONG,
     FsInformationClass: FS_INFORMATION_CLASS,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn RtlWakeAddressAll(
     Address: ?*const anyopaque,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub extern "ntdll" fn RtlWakeAddressSingle(
     Address: ?*const anyopaque,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub extern "ntdll" fn RtlWaitOnAddress(
     Address: ?*const anyopaque,
     CompareAddress: ?*const anyopaque,
     AddressSize: SIZE_T,
     Timeout: ?*const LARGE_INTEGER,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn RtlEqualUnicodeString(
     String1: *const UNICODE_STRING,
     String2: *const UNICODE_STRING,
     CaseInSensitive: BOOLEAN,
-) callconv(WINAPI) BOOLEAN;
+) callconv(.winapi) BOOLEAN;
 
 pub extern "ntdll" fn RtlUpcaseUnicodeChar(
     SourceCharacter: u16,
-) callconv(WINAPI) u16;
+) callconv(.winapi) u16;
 
 pub extern "ntdll" fn NtLockFile(
     FileHandle: HANDLE,
@@ -290,7 +289,7 @@ pub extern "ntdll" fn NtLockFile(
     Key: ?*ULONG,
     FailImmediately: BOOLEAN,
     ExclusiveLock: BOOLEAN,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtUnlockFile(
     FileHandle: HANDLE,
@@ -298,13 +297,13 @@ pub extern "ntdll" fn NtUnlockFile(
     ByteOffset: *const LARGE_INTEGER,
     Length: *const LARGE_INTEGER,
     Key: ?*ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtOpenKey(
     KeyHandle: *HANDLE,
     DesiredAccess: ACCESS_MASK,
     ObjectAttributes: OBJECT_ATTRIBUTES,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn RtlQueryRegistryValues(
     RelativeTo: ULONG,
@@ -312,7 +311,7 @@ pub extern "ntdll" fn RtlQueryRegistryValues(
     QueryTable: [*]RTL_QUERY_REGISTRY_TABLE,
     Context: ?*anyopaque,
     Environment: ?*anyopaque,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtReadVirtualMemory(
     ProcessHandle: HANDLE,
@@ -320,7 +319,7 @@ pub extern "ntdll" fn NtReadVirtualMemory(
     Buffer: LPVOID,
     NumberOfBytesToRead: SIZE_T,
     NumberOfBytesRead: ?*SIZE_T,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtWriteVirtualMemory(
     ProcessHandle: HANDLE,
@@ -328,7 +327,7 @@ pub extern "ntdll" fn NtWriteVirtualMemory(
     Buffer: LPCVOID,
     NumberOfBytesToWrite: SIZE_T,
     NumberOfBytesWritten: ?*SIZE_T,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn NtProtectVirtualMemory(
     ProcessHandle: HANDLE,
@@ -336,11 +335,11 @@ pub extern "ntdll" fn NtProtectVirtualMemory(
     NumberOfBytesToProtect: *SIZE_T,
     NewAccessProtection: ULONG,
     OldAccessProtection: *ULONG,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
 
 pub extern "ntdll" fn RtlExitUserProcess(
     ExitStatus: u32,
-) callconv(WINAPI) noreturn;
+) callconv(.winapi) noreturn;
 
 pub extern "ntdll" fn NtCreateNamedPipeFile(
     FileHandle: *HANDLE,
@@ -357,4 +356,4 @@ pub extern "ntdll" fn NtCreateNamedPipeFile(
     InboundQuota: ULONG,
     OutboundQuota: ULONG,
     DefaultTimeout: *LARGE_INTEGER,
-) callconv(WINAPI) NTSTATUS;
+) callconv(.winapi) NTSTATUS;
diff --git a/lib/std/os/windows/test.zig b/lib/std/os/windows/test.zig
index acaa7d1218..b4cecefbd7 100644
--- a/lib/std/os/windows/test.zig
+++ b/lib/std/os/windows/test.zig
@@ -250,7 +250,7 @@ test "loadWinsockExtensionFunction" {
         SendBufLen: windows.DWORD,
         BytesSent: *windows.DWORD,
         Overlapped: *windows.OVERLAPPED,
-    ) callconv(windows.WINAPI) windows.BOOL;
+    ) callconv(.winapi) windows.BOOL;
 
     _ = windows.loadWinsockExtensionFunction(
         LPFN_CONNECTEX,
diff --git a/lib/std/os/windows/ws2_32.zig b/lib/std/os/windows/ws2_32.zig
index f3a1fdca84..e8375dc2c1 100644
--- a/lib/std/os/windows/ws2_32.zig
+++ b/lib/std/os/windows/ws2_32.zig
@@ -2,7 +2,6 @@ const std = @import("../../std.zig");
 const assert = std.debug.assert;
 const windows = std.os.windows;
 
-const WINAPI = windows.WINAPI;
 const OVERLAPPED = windows.OVERLAPPED;
 const WORD = windows.WORD;
 const DWORD = windows.DWORD;
@@ -958,14 +957,14 @@ pub const LPCONDITIONPROC = *const fn (
     lpCalleeData: *WSABUF,
     g: *u32,
     dwCallbackData: usize,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub const LPWSAOVERLAPPED_COMPLETION_ROUTINE = *const fn (
     dwError: u32,
     cbTransferred: u32,
     lpOverlapped: *OVERLAPPED,
     dwFlags: u32,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub const FLOWSPEC = extern struct {
     TokenRate: u32,
@@ -1196,7 +1195,7 @@ pub const LPFN_TRANSMITFILE = *const fn (
     lpOverlapped: ?*OVERLAPPED,
     lpTransmitBuffers: ?*TRANSMIT_FILE_BUFFERS,
     dwReserved: u32,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub const LPFN_ACCEPTEX = *const fn (
     sListenSocket: SOCKET,
@@ -1207,7 +1206,7 @@ pub const LPFN_ACCEPTEX = *const fn (
     dwRemoteAddressLength: u32,
     lpdwBytesReceived: *u32,
     lpOverlapped: *OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub const LPFN_GETACCEPTEXSOCKADDRS = *const fn (
     lpOutputBuffer: *anyopaque,
@@ -1218,7 +1217,7 @@ pub const LPFN_GETACCEPTEXSOCKADDRS = *const fn (
     LocalSockaddrLength: *i32,
     RemoteSockaddr: **sockaddr,
     RemoteSockaddrLength: *i32,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub const LPFN_WSASENDMSG = *const fn (
     s: SOCKET,
@@ -1227,7 +1226,7 @@ pub const LPFN_WSASENDMSG = *const fn (
     lpNumberOfBytesSent: ?*u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub const LPFN_WSARECVMSG = *const fn (
     s: SOCKET,
@@ -1235,12 +1234,12 @@ pub const LPFN_WSARECVMSG = *const fn (
     lpdwNumberOfBytesRecv: ?*u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub const LPSERVICE_CALLBACK_PROC = *const fn (
     lParam: LPARAM,
     hAsyncTaskHandle: HANDLE,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub const SERVICE_ASYNC_INFO = extern struct {
     lpServiceCallbackProc: LPSERVICE_CALLBACK_PROC,
@@ -1252,7 +1251,7 @@ pub const LPLOOKUPSERVICE_COMPLETION_ROUTINE = *const fn (
     dwError: u32,
     dwBytes: u32,
     lpOverlapped: *OVERLAPPED,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub const fd_set = extern struct {
     fd_count: u32,
@@ -1725,41 +1724,41 @@ pub extern "ws2_32" fn accept(
     s: SOCKET,
     addr: ?*sockaddr,
     addrlen: ?*i32,
-) callconv(WINAPI) SOCKET;
+) callconv(.winapi) SOCKET;
 
 pub extern "ws2_32" fn bind(
     s: SOCKET,
     name: *const sockaddr,
     namelen: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn closesocket(
     s: SOCKET,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn connect(
     s: SOCKET,
     name: *const sockaddr,
     namelen: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn ioctlsocket(
     s: SOCKET,
     cmd: i32,
     argp: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn getpeername(
     s: SOCKET,
     name: *sockaddr,
     namelen: *i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn getsockname(
     s: SOCKET,
     name: *sockaddr,
     namelen: *i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn getsockopt(
     s: SOCKET,
@@ -1767,39 +1766,39 @@ pub extern "ws2_32" fn getsockopt(
     optname: i32,
     optval: [*]u8,
     optlen: *i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn htonl(
     hostlong: u32,
-) callconv(WINAPI) u32;
+) callconv(.winapi) u32;
 
 pub extern "ws2_32" fn htons(
     hostshort: u16,
-) callconv(WINAPI) u16;
+) callconv(.winapi) u16;
 
 pub extern "ws2_32" fn inet_addr(
     cp: ?[*]const u8,
-) callconv(WINAPI) u32;
+) callconv(.winapi) u32;
 
 pub extern "ws2_32" fn listen(
     s: SOCKET,
     backlog: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn ntohl(
     netlong: u32,
-) callconv(WINAPI) u32;
+) callconv(.winapi) u32;
 
 pub extern "ws2_32" fn ntohs(
     netshort: u16,
-) callconv(WINAPI) u16;
+) callconv(.winapi) u16;
 
 pub extern "ws2_32" fn recv(
     s: SOCKET,
     buf: [*]u8,
     len: i32,
     flags: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn recvfrom(
     s: SOCKET,
@@ -1808,7 +1807,7 @@ pub extern "ws2_32" fn recvfrom(
     flags: i32,
     from: ?*sockaddr,
     fromlen: ?*i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn select(
     nfds: i32,
@@ -1816,14 +1815,14 @@ pub extern "ws2_32" fn select(
     writefds: ?*fd_set,
     exceptfds: ?*fd_set,
     timeout: ?*const timeval,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn send(
     s: SOCKET,
     buf: [*]const u8,
     len: i32,
     flags: u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn sendto(
     s: SOCKET,
@@ -1832,7 +1831,7 @@ pub extern "ws2_32" fn sendto(
     flags: i32,
     to: *const sockaddr,
     tolen: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn setsockopt(
     s: SOCKET,
@@ -1840,37 +1839,37 @@ pub extern "ws2_32" fn setsockopt(
     optname: i32,
     optval: ?[*]const u8,
     optlen: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn shutdown(
     s: SOCKET,
     how: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn socket(
     af: i32,
     @"type": i32,
     protocol: i32,
-) callconv(WINAPI) SOCKET;
+) callconv(.winapi) SOCKET;
 
 pub extern "ws2_32" fn WSAStartup(
     wVersionRequired: WORD,
     lpWSAData: *WSADATA,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
-pub extern "ws2_32" fn WSACleanup() callconv(WINAPI) i32;
+pub extern "ws2_32" fn WSACleanup() callconv(.winapi) i32;
 
-pub extern "ws2_32" fn WSASetLastError(iError: i32) callconv(WINAPI) void;
+pub extern "ws2_32" fn WSASetLastError(iError: i32) callconv(.winapi) void;
 
-pub extern "ws2_32" fn WSAGetLastError() callconv(WINAPI) WinsockError;
+pub extern "ws2_32" fn WSAGetLastError() callconv(.winapi) WinsockError;
 
-pub extern "ws2_32" fn WSAIsBlocking() callconv(WINAPI) BOOL;
+pub extern "ws2_32" fn WSAIsBlocking() callconv(.winapi) BOOL;
 
-pub extern "ws2_32" fn WSAUnhookBlockingHook() callconv(WINAPI) i32;
+pub extern "ws2_32" fn WSAUnhookBlockingHook() callconv(.winapi) i32;
 
-pub extern "ws2_32" fn WSASetBlockingHook(lpBlockFunc: FARPROC) callconv(WINAPI) FARPROC;
+pub extern "ws2_32" fn WSASetBlockingHook(lpBlockFunc: FARPROC) callconv(.winapi) FARPROC;
 
-pub extern "ws2_32" fn WSACancelBlockingCall() callconv(WINAPI) i32;
+pub extern "ws2_32" fn WSACancelBlockingCall() callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAAsyncGetServByName(
     hWnd: HWND,
@@ -1879,7 +1878,7 @@ pub extern "ws2_32" fn WSAAsyncGetServByName(
     proto: ?[*:0]const u8,
     buf: [*]u8,
     buflen: i32,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 pub extern "ws2_32" fn WSAAsyncGetServByPort(
     hWnd: HWND,
@@ -1888,7 +1887,7 @@ pub extern "ws2_32" fn WSAAsyncGetServByPort(
     proto: ?[*:0]const u8,
     buf: [*]u8,
     buflen: i32,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 pub extern "ws2_32" fn WSAAsyncGetProtoByName(
     hWnd: HWND,
@@ -1896,7 +1895,7 @@ pub extern "ws2_32" fn WSAAsyncGetProtoByName(
     name: [*:0]const u8,
     buf: [*]u8,
     buflen: i32,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
 pub extern "ws2_32" fn WSAAsyncGetProtoByNumber(
     hWnd: HWND,
@@ -1904,16 +1903,16 @@ pub extern "ws2_32" fn WSAAsyncGetProtoByNumber(
     number: i32,
     buf: [*]u8,
     buflen: i32,
-) callconv(WINAPI) HANDLE;
+) callconv(.winapi) HANDLE;
 
-pub extern "ws2_32" fn WSACancelAsyncRequest(hAsyncTaskHandle: HANDLE) callconv(WINAPI) i32;
+pub extern "ws2_32" fn WSACancelAsyncRequest(hAsyncTaskHandle: HANDLE) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAAsyncSelect(
     s: SOCKET,
     hWnd: HWND,
     wMsg: u32,
     lEvent: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAAccept(
     s: SOCKET,
@@ -1921,9 +1920,9 @@ pub extern "ws2_32" fn WSAAccept(
     addrlen: ?*i32,
     lpfnCondition: ?LPCONDITIONPROC,
     dwCallbackData: usize,
-) callconv(WINAPI) SOCKET;
+) callconv(.winapi) SOCKET;
 
-pub extern "ws2_32" fn WSACloseEvent(hEvent: HANDLE) callconv(WINAPI) BOOL;
+pub extern "ws2_32" fn WSACloseEvent(hEvent: HANDLE) callconv(.winapi) BOOL;
 
 pub extern "ws2_32" fn WSAConnect(
     s: SOCKET,
@@ -1933,7 +1932,7 @@ pub extern "ws2_32" fn WSAConnect(
     lpCalleeData: ?*WSABUF,
     lpSQOS: ?*QOS,
     lpGQOS: ?*QOS,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAConnectByNameW(
     s: SOCKET,
@@ -1945,7 +1944,7 @@ pub extern "ws2_32" fn WSAConnectByNameW(
     RemoteAddress: ?*sockaddr,
     timeout: ?*const timeval,
     Reserved: *OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "ws2_32" fn WSAConnectByNameA(
     s: SOCKET,
@@ -1957,7 +1956,7 @@ pub extern "ws2_32" fn WSAConnectByNameA(
     RemoteAddress: ?*sockaddr,
     timeout: ?*const timeval,
     Reserved: *OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "ws2_32" fn WSAConnectByList(
     s: SOCKET,
@@ -1968,45 +1967,45 @@ pub extern "ws2_32" fn WSAConnectByList(
     RemoteAddress: ?*sockaddr,
     timeout: ?*const timeval,
     Reserved: *OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
-pub extern "ws2_32" fn WSACreateEvent() callconv(WINAPI) HANDLE;
+pub extern "ws2_32" fn WSACreateEvent() callconv(.winapi) HANDLE;
 
 pub extern "ws2_32" fn WSADuplicateSocketA(
     s: SOCKET,
     dwProcessId: u32,
     lpProtocolInfo: *WSAPROTOCOL_INFOA,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSADuplicateSocketW(
     s: SOCKET,
     dwProcessId: u32,
     lpProtocolInfo: *WSAPROTOCOL_INFOW,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAEnumNetworkEvents(
     s: SOCKET,
     hEventObject: HANDLE,
     lpNetworkEvents: *WSANETWORKEVENTS,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAEnumProtocolsA(
     lpiProtocols: ?*i32,
     lpProtocolBuffer: ?*WSAPROTOCOL_INFOA,
     lpdwBufferLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAEnumProtocolsW(
     lpiProtocols: ?*i32,
     lpProtocolBuffer: ?*WSAPROTOCOL_INFOW,
     lpdwBufferLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAEventSelect(
     s: SOCKET,
     hEventObject: HANDLE,
     lNetworkEvents: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAGetOverlappedResult(
     s: SOCKET,
@@ -2014,25 +2013,25 @@ pub extern "ws2_32" fn WSAGetOverlappedResult(
     lpcbTransfer: *u32,
     fWait: BOOL,
     lpdwFlags: *u32,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "ws2_32" fn WSAGetQOSByName(
     s: SOCKET,
     lpQOSName: *WSABUF,
     lpQOS: *QOS,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "ws2_32" fn WSAHtonl(
     s: SOCKET,
     hostlong: u32,
     lpnetlong: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAHtons(
     s: SOCKET,
     hostshort: u16,
     lpnetshort: *u16,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAIoctl(
     s: SOCKET,
@@ -2044,7 +2043,7 @@ pub extern "ws2_32" fn WSAIoctl(
     lpcbBytesReturned: *u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAJoinLeaf(
     s: SOCKET,
@@ -2055,19 +2054,19 @@ pub extern "ws2_32" fn WSAJoinLeaf(
     lpSQOS: ?*QOS,
     lpGQOS: ?*QOS,
     dwFlags: u32,
-) callconv(WINAPI) SOCKET;
+) callconv(.winapi) SOCKET;
 
 pub extern "ws2_32" fn WSANtohl(
     s: SOCKET,
     netlong: u32,
     lphostlong: *u32,
-) callconv(WINAPI) u32;
+) callconv(.winapi) u32;
 
 pub extern "ws2_32" fn WSANtohs(
     s: SOCKET,
     netshort: u16,
     lphostshort: *u16,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSARecv(
     s: SOCKET,
@@ -2077,12 +2076,12 @@ pub extern "ws2_32" fn WSARecv(
     lpFlags: *u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSARecvDisconnect(
     s: SOCKET,
     lpInboundDisconnectData: ?*WSABUF,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSARecvFrom(
     s: SOCKET,
@@ -2094,9 +2093,9 @@ pub extern "ws2_32" fn WSARecvFrom(
     lpFromlen: ?*i32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
-pub extern "ws2_32" fn WSAResetEvent(hEvent: HANDLE) callconv(WINAPI) i32;
+pub extern "ws2_32" fn WSAResetEvent(hEvent: HANDLE) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSASend(
     s: SOCKET,
@@ -2106,7 +2105,7 @@ pub extern "ws2_32" fn WSASend(
     dwFlags: u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSASendMsg(
     s: SOCKET,
@@ -2115,7 +2114,7 @@ pub extern "ws2_32" fn WSASendMsg(
     lpNumberOfBytesSent: ?*u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSARecvMsg(
     s: SOCKET,
@@ -2123,12 +2122,12 @@ pub extern "ws2_32" fn WSARecvMsg(
     lpdwNumberOfBytesRecv: ?*u32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSASendDisconnect(
     s: SOCKET,
     lpOutboundDisconnectData: ?*WSABUF,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSASendTo(
     s: SOCKET,
@@ -2140,11 +2139,11 @@ pub extern "ws2_32" fn WSASendTo(
     iToLen: i32,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRounte: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSASetEvent(
     hEvent: HANDLE,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "ws2_32" fn WSASocketA(
     af: i32,
@@ -2153,7 +2152,7 @@ pub extern "ws2_32" fn WSASocketA(
     lpProtocolInfo: ?*WSAPROTOCOL_INFOA,
     g: u32,
     dwFlags: u32,
-) callconv(WINAPI) SOCKET;
+) callconv(.winapi) SOCKET;
 
 pub extern "ws2_32" fn WSASocketW(
     af: i32,
@@ -2162,7 +2161,7 @@ pub extern "ws2_32" fn WSASocketW(
     lpProtocolInfo: ?*WSAPROTOCOL_INFOW,
     g: u32,
     dwFlags: u32,
-) callconv(WINAPI) SOCKET;
+) callconv(.winapi) SOCKET;
 
 pub extern "ws2_32" fn WSAWaitForMultipleEvents(
     cEvents: u32,
@@ -2170,7 +2169,7 @@ pub extern "ws2_32" fn WSAWaitForMultipleEvents(
     fWaitAll: BOOL,
     dwTimeout: u32,
     fAlertable: BOOL,
-) callconv(WINAPI) u32;
+) callconv(.winapi) u32;
 
 pub extern "ws2_32" fn WSAAddressToStringA(
     lpsaAddress: *sockaddr,
@@ -2178,7 +2177,7 @@ pub extern "ws2_32" fn WSAAddressToStringA(
     lpProtocolInfo: ?*WSAPROTOCOL_INFOA,
     lpszAddressString: [*]u8,
     lpdwAddressStringLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAAddressToStringW(
     lpsaAddress: *sockaddr,
@@ -2186,7 +2185,7 @@ pub extern "ws2_32" fn WSAAddressToStringW(
     lpProtocolInfo: ?*WSAPROTOCOL_INFOW,
     lpszAddressString: [*]u16,
     lpdwAddressStringLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAStringToAddressA(
     AddressString: [*:0]const u8,
@@ -2194,7 +2193,7 @@ pub extern "ws2_32" fn WSAStringToAddressA(
     lpProtocolInfo: ?*WSAPROTOCOL_INFOA,
     lpAddress: *sockaddr,
     lpAddressLength: *i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAStringToAddressW(
     AddressString: [*:0]const u16,
@@ -2202,26 +2201,26 @@ pub extern "ws2_32" fn WSAStringToAddressW(
     lpProtocolInfo: ?*WSAPROTOCOL_INFOW,
     lpAddrses: *sockaddr,
     lpAddressLength: *i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAProviderConfigChange(
     lpNotificationHandle: *HANDLE,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPWSAOVERLAPPED_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn WSAPoll(
     fdArray: [*]WSAPOLLFD,
     fds: u32,
     timeout: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn WSARecvEx(
     s: SOCKET,
     buf: [*]u8,
     len: i32,
     flags: *i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn TransmitFile(
     hSocket: SOCKET,
@@ -2231,7 +2230,7 @@ pub extern "mswsock" fn TransmitFile(
     lpOverlapped: ?*OVERLAPPED,
     lpTransmitBuffers: ?*TRANSMIT_FILE_BUFFERS,
     dwReserved: u32,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "mswsock" fn AcceptEx(
     sListenSocket: SOCKET,
@@ -2242,7 +2241,7 @@ pub extern "mswsock" fn AcceptEx(
     dwRemoteAddressLength: u32,
     lpdwBytesReceived: *u32,
     lpOverlapped: *OVERLAPPED,
-) callconv(WINAPI) BOOL;
+) callconv(.winapi) BOOL;
 
 pub extern "mswsock" fn GetAcceptExSockaddrs(
     lpOutputBuffer: *anyopaque,
@@ -2253,24 +2252,24 @@ pub extern "mswsock" fn GetAcceptExSockaddrs(
     LocalSockaddrLength: *i32,
     RemoteSockaddr: **sockaddr,
     RemoteSockaddrLength: *i32,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub extern "ws2_32" fn WSAProviderCompleteAsyncCall(
     hAsyncCall: HANDLE,
     iRetCode: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn EnumProtocolsA(
     lpiProtocols: ?*i32,
     lpProtocolBuffer: *anyopaque,
     lpdwBufferLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn EnumProtocolsW(
     lpiProtocols: ?*i32,
     lpProtocolBuffer: *anyopaque,
     lpdwBufferLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn GetAddressByNameA(
     dwNameSpace: u32,
@@ -2282,7 +2281,7 @@ pub extern "mswsock" fn GetAddressByNameA(
     lpCsaddrBuffer: *anyopaque,
     lpAliasBuffer: ?[*:0]const u8,
     lpdwAliasBufferLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn GetAddressByNameW(
     dwNameSpace: u32,
@@ -2295,36 +2294,36 @@ pub extern "mswsock" fn GetAddressByNameW(
     ldwBufferLEngth: *u32,
     lpAliasBuffer: ?[*:0]u16,
     lpdwAliasBufferLength: *u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn GetTypeByNameA(
     lpServiceName: [*:0]u8,
     lpServiceType: *GUID,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn GetTypeByNameW(
     lpServiceName: [*:0]u16,
     lpServiceType: *GUID,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn GetNameByTypeA(
     lpServiceType: *GUID,
     lpServiceName: [*:0]u8,
     dwNameLength: u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "mswsock" fn GetNameByTypeW(
     lpServiceType: *GUID,
     lpServiceName: [*:0]u16,
     dwNameLength: u32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn getaddrinfo(
     pNodeName: ?[*:0]const u8,
     pServiceName: ?[*:0]const u8,
     pHints: ?*const addrinfoa,
     ppResult: *?*addrinfoa,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn GetAddrInfoExA(
     pName: ?[*:0]const u8,
@@ -2336,23 +2335,23 @@ pub extern "ws2_32" fn GetAddrInfoExA(
     timeout: ?*timeval,
     lpOverlapped: ?*OVERLAPPED,
     lpCompletionRoutine: ?LPLOOKUPSERVICE_COMPLETION_ROUTINE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn GetAddrInfoExCancel(
     lpHandle: *HANDLE,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn GetAddrInfoExOverlappedResult(
     lpOverlapped: *OVERLAPPED,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "ws2_32" fn freeaddrinfo(
     pAddrInfo: ?*addrinfoa,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub extern "ws2_32" fn FreeAddrInfoEx(
     pAddrInfoEx: ?*addrinfoexA,
-) callconv(WINAPI) void;
+) callconv(.winapi) void;
 
 pub extern "ws2_32" fn getnameinfo(
     pSockaddr: *const sockaddr,
@@ -2362,8 +2361,8 @@ pub extern "ws2_32" fn getnameinfo(
     pServiceBuffer: ?[*]u8,
     ServiceBufferName: u32,
     Flags: i32,
-) callconv(WINAPI) i32;
+) callconv(.winapi) i32;
 
 pub extern "iphlpapi" fn if_nametoindex(
     InterfaceName: [*:0]const u8,
-) callconv(WINAPI) u32;
+) callconv(.winapi) u32;
diff --git a/src/crash_report.zig b/src/crash_report.zig
index d9f8bac350..45410890a5 100644
--- a/src/crash_report.zig
+++ b/src/crash_report.zig
@@ -229,7 +229,7 @@ const WindowsSegfaultMessage = union(enum) {
     illegal_instruction: void,
 };
 
-fn handleSegfaultWindows(info: *windows.EXCEPTION_POINTERS) callconv(windows.WINAPI) c_long {
+fn handleSegfaultWindows(info: *windows.EXCEPTION_POINTERS) callconv(.winapi) c_long {
     switch (info.ExceptionRecord.ExceptionCode) {
         windows.EXCEPTION_DATATYPE_MISALIGNMENT => handleSegfaultWindowsExtra(info, .{ .literal = "Unaligned Memory Access" }),
         windows.EXCEPTION_ACCESS_VIOLATION => handleSegfaultWindowsExtra(info, .segfault),