diff --git a/dlls/msvcp90/msvcp90_main.c b/dlls/msvcp90/msvcp90_main.c
index 7a7aafe9718..496efa90f6e 100644
--- a/dlls/msvcp90/msvcp90_main.c
+++ b/dlls/msvcp90/msvcp90_main.c
@@ -92,6 +92,7 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
             init_io(hinstDLL);
             break;
         case DLL_PROCESS_DETACH:
+            if (lpvReserved) break;
             free_io();
             free_locale();
             free_lockit();