diff --git a/build.zig b/build.zig
index ed9856a437..d6e365b02d 100644
--- a/build.zig
+++ b/build.zig
@@ -372,6 +372,7 @@ fn addLibUserlandStep(b: *Builder) void {
     artifact.bundle_compiler_rt = true;
     artifact.setTarget(builtin.arch, builtin.os, builtin.abi);
     artifact.linkSystemLibrary("c");
+    artifact.linkSystemLibrary("ntdll");
     const libuserland_step = b.step("libuserland", "Build the userland compiler library for use in stage1");
     libuserland_step.dependOn(&artifact.step);
 
diff --git a/src/buffer.hpp b/src/buffer.hpp
index d4a911fc21..d7254c18a7 100644
--- a/src/buffer.hpp
+++ b/src/buffer.hpp
@@ -136,11 +136,21 @@ static inline bool buf_eql_mem(Buf *buf, const char *mem, size_t mem_len) {
     return mem_eql_mem(buf_ptr(buf), buf_len(buf), mem, mem_len);
 }
 
+static inline bool buf_eql_mem_ignore_case(Buf *buf, const char *mem, size_t mem_len) {
+    assert(buf->list.length);
+    return mem_eql_mem_ignore_case(buf_ptr(buf), buf_len(buf), mem, mem_len);
+}
+
 static inline bool buf_eql_str(Buf *buf, const char *str) {
     assert(buf->list.length);
     return buf_eql_mem(buf, str, strlen(str));
 }
 
+static inline bool buf_eql_str_ignore_case(Buf *buf, const char *str) {
+    assert(buf->list.length);
+    return buf_eql_mem_ignore_case(buf, str, strlen(str));
+}
+
 static inline bool buf_starts_with_mem(Buf *buf, const char *mem, size_t mem_len) {
     if (buf_len(buf) < mem_len) {
         return false;
diff --git a/src/util.hpp b/src/util.hpp
index 6f26725135..1fa33b30f9 100644
--- a/src/util.hpp
+++ b/src/util.hpp
@@ -12,6 +12,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <assert.h>
+#include <ctype.h>
 
 #if defined(_MSC_VER)
 
@@ -161,6 +162,15 @@ static inline bool mem_eql_mem(const char *a_ptr, size_t a_len, const char *b_pt
         return false;
     return memcmp(a_ptr, b_ptr, a_len) == 0;
 }
+static inline bool mem_eql_mem_ignore_case(const char *a_ptr, size_t a_len, const char *b_ptr, size_t b_len) {
+    if (a_len != b_len)
+        return false;
+    for (size_t i = 0; i < a_len; i += 1) {
+        if (tolower(a_ptr[i]) != tolower(b_ptr[i]))
+            return false;
+    }
+    return true;
+}
 
 static inline bool mem_eql_str(const char *mem, size_t mem_len, const char *str) {
     return mem_eql_mem(mem, mem_len, str, strlen(str));
diff --git a/std/os/windows.zig b/std/os/windows.zig
index aa97671298..ac76e8f58f 100644
--- a/std/os/windows.zig
+++ b/std/os/windows.zig
@@ -267,7 +267,7 @@ pub fn GetQueuedCompletionStatus(
 }
 
 pub fn CloseHandle(hObject: HANDLE) void {
-    assert(ntdll.NtClose(hObject) == STATUS.SUCCESS);
+    assert(kernel32.CloseHandle(hObject) != 0);
 }
 
 pub fn FindClose(hFindFile: HANDLE) void {
@@ -820,24 +820,9 @@ pub fn sliceToPrefixedFileW(s: []const u8) ![PATH_MAX_WIDE + 1]u16 {
     return sliceToPrefixedSuffixedFileW(s, [_]u16{0});
 }
 
-/// TODO once https://github.com/ziglang/zig/issues/2765 and https://github.com/ziglang/zig/issues/2761 are both solved,
-/// this can be removed. Callsites that do not have performance bottlenecks
-/// in this function should call `sliceToPrefixedFileW` to be future-proof.
-pub fn sliceToPrefixedFileW_elidecopy(s: []const u8, result: *[PATH_MAX_WIDE + 1]u16) !void {
-    return sliceToPrefixedSuffixedFileW_elidecopy(s, [_]u16{0}, result);
-}
-
 pub fn sliceToPrefixedSuffixedFileW(s: []const u8, comptime suffix: []const u16) ![PATH_MAX_WIDE + suffix.len]u16 {
     // TODO https://github.com/ziglang/zig/issues/2765
     var result: [PATH_MAX_WIDE + suffix.len]u16 = undefined;
-    try sliceToPrefixedSuffixedFileW_elidecopy(s, suffix, &result);
-    return result;
-}
-
-/// TODO once https://github.com/ziglang/zig/issues/2765 and https://github.com/ziglang/zig/issues/2761 are both solved,
-/// this can be removed. Callsites that do not have performance bottlenecks
-/// in this function should call `sliceToPrefixedSuffixedFileW` to be future-proof.
-pub fn sliceToPrefixedSuffixedFileW_elidecopy(s: []const u8, comptime suffix: []const u16, result: *[PATH_MAX_WIDE + suffix.len]u16) !void {
     // > File I/O functions in the Windows API convert "/" to "\" as part of
     // > converting the name to an NT-style name, except when using the "\\?\"
     // > prefix as detailed in the following sections.
@@ -859,6 +844,7 @@ pub fn sliceToPrefixedSuffixedFileW_elidecopy(s: []const u8, comptime suffix: []
     assert(end_index <= result.len);
     if (end_index + suffix.len > result.len) return error.NameTooLong;
     mem.copy(u16, result[end_index..], suffix);
+    return result;
 }
 
 inline fn MAKELANGID(p: c_ushort, s: c_ushort) LANGID {
diff --git a/std/unicode.zig b/std/unicode.zig
index 6d47675ac3..2e96147166 100644
--- a/std/unicode.zig
+++ b/std/unicode.zig
@@ -577,7 +577,7 @@ pub fn utf8ToUtf16Le(utf16le: []u16, utf8: []const u8) !usize {
             },
             2, 3, 4 => {
                 const next_src_i = src_i + n;
-                const codepoint = try utf8Decode(utf8[src_i..next_src_i]);
+                const codepoint = utf8Decode(utf8[src_i..next_src_i]) catch return error.InvalidUtf8;
                 const short = @intCast(u16, codepoint); // TODO surrogate pairs
                 utf16le[dest_i] = switch (builtin.endian) {
                     .Little => short,
@@ -586,7 +586,7 @@ pub fn utf8ToUtf16Le(utf16le: []u16, utf8: []const u8) !usize {
                 dest_i += 1;
                 src_i = next_src_i;
             },
-            else => return error.Utf8InvalidStartByte,
+            else => return error.InvalidUtf8,
         }
     }
     return dest_i;