diff --git a/lib/std/os/windows/ws2_32.zig b/lib/std/os/windows/ws2_32.zig
index d467a60d178071dbd1a9f1d5871874d8716bacd7..abc858b24a98156ba9125342e42b82eb7881ddc3 100644
--- a/lib/std/os/windows/ws2_32.zig
+++ b/lib/std/os/windows/ws2_32.zig
@@ -728,7 +728,7 @@ pub extern "ws2_32" fn WSARecvFrom(
     lpNumberOfBytesRecvd: ?*DWORD,
     lpFlags: *DWORD,
     lpFrom: ?*sockaddr,
-    lpFromlen: socklen_t,
+    lpFromlen: ?*socklen_t,
     lpOverlapped: ?*WSAOVERLAPPED,
     lpCompletionRoutine: ?WSAOVERLAPPED_COMPLETION_ROUTINE,
 ) callconv(.Stdcall) c_int;