diff --git a/lib/std/os.zig b/lib/std/os.zig
index 280f4aa710..832e2901af 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -1147,7 +1147,7 @@ pub const LockCmd = enum {
 };
 
 /// Attempts to get lock the file, blocking if the file is locked.
-pub fn fcntlFlock(fd: fd_t, lock_cmd: LockCmd, flock_p: *const Flock) OpenError!void {
+pub fn fcntlFlock(fd: fd_t, lock_cmd: LockCmd, flock_p: *Flock) OpenError!void {
     const cmd: i32 = cmdval: {
         switch (lock_cmd) {
             .GetLock => break :cmdval F_GETLK,
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 4b29a1cc27..f47b0b8e3a 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -219,8 +219,8 @@ pub fn mmap(address: ?[*]u8, length: usize, prot: usize, flags: u32, fd: i32, of
     }
 }
 
-pub fn fcntl(fd: fd_t, cmd: i32, flock_p: *const c_void) usize {
-    return syscall3(SYS_fcntl, @bitCast(usize, @as(isize, fd)), @bitCast(usize, @as(isize, cmd)), @ptrToInt(flock_p));
+pub fn fcntl(fd: fd_t, cmd: i32, arg: ?*c_void) usize {
+    return syscall3(SYS_fcntl, @bitCast(usize, @as(isize, fd)), @bitCast(usize, @as(isize, cmd)), @ptrToInt(arg));
 }
 
 pub fn mprotect(address: [*]const u8, length: usize, protection: usize) usize {