diff --git a/lib/std/fs/File.zig b/lib/std/fs/File.zig
index ba0f29fd871cdca50158c5f8f370b495c83520fc..be540414854e004fe84e90a6a01fdefd5024a73c 100644
--- a/lib/std/fs/File.zig
+++ b/lib/std/fs/File.zig
@@ -32,11 +32,7 @@ pub const Kind = Io.File.Kind;
 /// the `touch` command, which would correspond to `0o644`. However, POSIX
 /// libc implementations use `0o666` inside `fopen` and then rely on the
 /// process-scoped "umask" setting to adjust this number for file creation.
-pub const default_mode = switch (builtin.os.tag) {
-    .windows => 0,
-    .wasi => 0,
-    else => 0o666,
-};
+pub const default_mode: Mode = if (Mode == u0) 0 else 0o666;
 
 /// Deprecated in favor of `Io.File.OpenError`.
 pub const OpenError = Io.File.OpenError || error{WouldBlock};
diff --git a/lib/std/posix.zig b/lib/std/posix.zig
index f708dfeabab1d22cf10d670b5014b749b7b96fba..b240a6583d839449985ce34925b38333d0f1a858 100644
--- a/lib/std/posix.zig
+++ b/lib/std/posix.zig
@@ -52,8 +52,9 @@ else switch (native_os) {
         pub const fd_t = void;
         pub const uid_t = void;
         pub const gid_t = void;
-        pub const mode_t = void;
+        pub const mode_t = u0;
         pub const ino_t = void;
+        pub const IFNAMESIZE = {};
     },
 };