diff --git a/lib/std/c.zig b/lib/std/c.zig
index b4e5fc7392..1b3f403ab5 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -330,3 +330,8 @@ pub const FILE = @Type(.Opaque);
 pub extern "c" fn dlopen(path: [*:0]const u8, mode: c_int) ?*c_void;
 pub extern "c" fn dlclose(handle: *c_void) c_int;
 pub extern "c" fn dlsym(handle: ?*c_void, symbol: [*:0]const u8) ?*c_void;
+
+pub extern "c" fn sync() void;
+pub extern "c" fn syncfs(fd: c_int) c_int;
+pub extern "c" fn fsync(fd: c_int) c_int;
+pub extern "c" fn fdatasync(fd: c_int) c_int;
diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index 576125e2a3..0d8d2cc0db 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -555,3 +555,23 @@ test "signalfd" {
         return error.SkipZigTest;
     _ = std.os.signalfd;
 }
+
+test "sync" {
+    if (builtin.os.tag != .linux and builtin.os.tag != .windows)
+        return error.SkipZigTest;
+
+    var tmp = tmpDir(.{});
+    defer tmp.cleanup();
+
+    const test_out_file = "os_tmp_test";
+    const file = try tmp.dir.createFile(test_out_file, .{});
+    defer {
+        file.close();
+        tmp.dir.deleteFile(test_out_file) catch {};
+    }
+
+    try os.syncfs(file.handle);
+    try os.fsync(file.handle);
+    try os.fdatasync(file.handle);
+    os.sync();
+}