diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index fe645c1a059..e345e874088 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -866,6 +866,7 @@ BOOL WINAPI DllMain(HINSTANCE hInstDLL, DWORD fdwReason, LPVOID fImpLoad)
         break;
     case DLL_PROCESS_DETACH:
         free_per_thread_data();
+        DeleteCriticalSection(&csWSgetXXXbyYYY);
         num_startup = 0;
         break;
     case DLL_THREAD_DETACH: