diff --git a/starboard/shared/win32/socket_set_tcp_window_scaling.cc b/starboard/shared/win32/socket_set_tcp_window_scaling.cc
index 0e7306605a21..091af3cc51e9 100644
--- a/starboard/shared/win32/socket_set_tcp_window_scaling.cc
+++ b/starboard/shared/win32/socket_set_tcp_window_scaling.cc
@@ -30,6 +30,9 @@ bool SbSocketSetTcpWindowScaling(SbSocket socket, bool enable_window_scaling) {
   // later, receive window auto-tuning is enabled and the TCP window scale
   // factor is reduced to 2 from the default value of 8."
 
+  if (socket == kSbSocketInvalid)
+    return false;
+
   const ULONG target_os_version =
       enable_window_scaling ? NTDDI_VISTA : NTDDI_WS03;
   WSA_COMPATIBILITY_MODE compatibility_mode = {WsaBehaviorAutoTuning,