diff --git a/lib/std/Io/Threaded.zig b/lib/std/Io/Threaded.zig
index 1d137ebe85..4f2582885b 100644
--- a/lib/std/Io/Threaded.zig
+++ b/lib/std/Io/Threaded.zig
@@ -193,7 +193,11 @@ pub fn io(t: *Threaded) Io {
                 .wasi => dirCreateFileWasi,
                 else => dirCreateFilePosix,
             },
-            .dirOpenFile = dirOpenFile,
+            .dirOpenFile = switch (builtin.os.tag) {
+                .windows => @panic("TODO"),
+                .wasi => dirOpenFileWasi,
+                else => dirOpenFilePosix,
+            },
             .fileClose = fileClose,
             .fileWriteStreaming = fileWriteStreaming,
             .fileWritePositional = fileWritePositional,
@@ -1451,7 +1455,7 @@ fn dirCreateFileWasi(
     }
 }
 
-fn dirOpenFile(
+fn dirOpenFilePosix(
     userdata: ?*anyopaque,
     dir: Io.Dir,
     sub_path: []const u8,
@@ -1584,6 +1588,74 @@ fn dirOpenFile(
     return .{ .handle = fd };
 }
 
+fn dirOpenFileWasi(
+    userdata: ?*anyopaque,
+    dir: Io.Dir,
+    sub_path: []const u8,
+    flags: Io.File.OpenFlags,
+) Io.File.OpenError!Io.File {
+    if (builtin.link_libc) return dirOpenFilePosix(userdata, dir, sub_path, flags);
+    const t: *Threaded = @ptrCast(@alignCast(userdata));
+    const wasi = std.os.wasi;
+    var base: std.os.wasi.rights_t = .{};
+    // POLL_FD_READWRITE only grants extra rights if the corresponding FD_READ and/or FD_WRITE
+    // is also set.
+    if (flags.isRead()) {
+        base.FD_READ = true;
+        base.FD_TELL = true;
+        base.FD_SEEK = true;
+        base.FD_FILESTAT_GET = true;
+        base.POLL_FD_READWRITE = true;
+    }
+    if (flags.isWrite()) {
+        base.FD_WRITE = true;
+        base.FD_TELL = true;
+        base.FD_SEEK = true;
+        base.FD_DATASYNC = true;
+        base.FD_FDSTAT_SET_FLAGS = true;
+        base.FD_SYNC = true;
+        base.FD_ALLOCATE = true;
+        base.FD_ADVISE = true;
+        base.FD_FILESTAT_SET_TIMES = true;
+        base.FD_FILESTAT_SET_SIZE = true;
+        base.POLL_FD_READWRITE = true;
+    }
+    const lookup_flags: wasi.lookupflags_t = .{};
+    const oflags: wasi.oflags_t = .{};
+    const inheriting: wasi.rights_t = .{};
+    const fdflags: wasi.fdflags_t = .{};
+    var fd: posix.fd_t = undefined;
+    while (true) {
+        try t.checkCancel();
+        switch (wasi.path_open(dir.handle, lookup_flags, sub_path.ptr, sub_path.len, oflags, base, inheriting, fdflags, &fd)) {
+            .SUCCESS => return .{ .handle = fd },
+            .INTR => continue,
+            .CANCELED => return error.Canceled,
+
+            .FAULT => |err| return errnoBug(err),
+            .BADF => |err| return errnoBug(err), // File descriptor used after closed.
+            .ACCES => return error.AccessDenied,
+            .FBIG => return error.FileTooBig,
+            .OVERFLOW => return error.FileTooBig,
+            .ISDIR => return error.IsDir,
+            .LOOP => return error.SymLinkLoop,
+            .MFILE => return error.ProcessFdQuotaExceeded,
+            .NFILE => return error.SystemFdQuotaExceeded,
+            .NODEV => return error.NoDevice,
+            .NOENT => return error.FileNotFound,
+            .NOMEM => return error.SystemResources,
+            .NOTDIR => return error.NotDir,
+            .PERM => return error.PermissionDenied,
+            .BUSY => return error.DeviceBusy,
+            .NOTCAPABLE => return error.AccessDenied,
+            .NAMETOOLONG => return error.NameTooLong,
+            .INVAL => return error.BadPathName,
+            .ILSEQ => return error.BadPathName,
+            else => |err| return posix.unexpectedErrno(err),
+        }
+    }
+}
+
 fn fileClose(userdata: ?*anyopaque, file: Io.File) void {
     const t: *Threaded = @ptrCast(@alignCast(userdata));
     _ = t;
@@ -3319,7 +3391,7 @@ fn clockToPosix(clock: Io.Clock) posix.clockid_t {
 
 fn clockToWasi(clock: Io.Clock) std.os.wasi.clockid_t {
     return switch (clock) {
-        .realtime => .REALTIME,
+        .real => .REALTIME,
         .awake => .MONOTONIC,
         .boot => .MONOTONIC,
         .cpu_process => .PROCESS_CPUTIME_ID,
diff --git a/lib/std/fs/Dir.zig b/lib/std/fs/Dir.zig
index 6da4bab684..615c63efa6 100644
--- a/lib/std/fs/Dir.zig
+++ b/lib/std/fs/Dir.zig
@@ -858,33 +858,6 @@ pub fn openFile(self: Dir, sub_path: []const u8, flags: File.OpenFlags) File.Ope
         const path_w = try windows.sliceToPrefixedFileW(self.fd, sub_path);
         return self.openFileW(path_w.span(), flags);
     }
-    if (native_os == .wasi and !builtin.link_libc) {
-        var base: std.os.wasi.rights_t = .{};
-        // POLL_FD_READWRITE only grants extra rights if the corresponding FD_READ and/or FD_WRITE
-        // is also set.
-        if (flags.isRead()) {
-            base.FD_READ = true;
-            base.FD_TELL = true;
-            base.FD_SEEK = true;
-            base.FD_FILESTAT_GET = true;
-            base.POLL_FD_READWRITE = true;
-        }
-        if (flags.isWrite()) {
-            base.FD_WRITE = true;
-            base.FD_TELL = true;
-            base.FD_SEEK = true;
-            base.FD_DATASYNC = true;
-            base.FD_FDSTAT_SET_FLAGS = true;
-            base.FD_SYNC = true;
-            base.FD_ALLOCATE = true;
-            base.FD_ADVISE = true;
-            base.FD_FILESTAT_SET_TIMES = true;
-            base.FD_FILESTAT_SET_SIZE = true;
-            base.POLL_FD_READWRITE = true;
-        }
-        const fd = try posix.openatWasi(self.fd, sub_path, .{}, .{}, .{}, base, .{});
-        return .{ .handle = fd };
-    }
     var threaded: Io.Threaded = .init_single_threaded;
     const io = threaded.io();
     return .adaptFromNewApi(try Io.Dir.openFile(self.adaptToNewApi(), io, sub_path, flags));
diff --git a/lib/std/fs/test.zig b/lib/std/fs/test.zig
index 052afc3a02..a20be08fcb 100644
--- a/lib/std/fs/test.zig
+++ b/lib/std/fs/test.zig
@@ -1407,7 +1407,7 @@ test "setEndPos" {
         try f.setEndPos(initial_size);
         try testing.expectEqual(initial_size, try f.getEndPos());
         try reader.seekTo(0);
-        try testing.expectEqual(initial_size, reader.interface.readSliceShort(&buffer));
+        try testing.expectEqual(initial_size, try reader.interface.readSliceShort(&buffer));
         try testing.expectEqualStrings("ninebytes", buffer[0..@intCast(initial_size)]);
     }
 
@@ -1416,7 +1416,7 @@ test "setEndPos" {
         try f.setEndPos(larger);
         try testing.expectEqual(larger, try f.getEndPos());
         try reader.seekTo(0);
-        try testing.expectEqual(larger, reader.interface.readSliceShort(&buffer));
+        try testing.expectEqual(larger, try reader.interface.readSliceShort(&buffer));
         try testing.expectEqualStrings("ninebytes\x00\x00\x00\x00", buffer[0..@intCast(larger)]);
     }