ole32/tests: Prevent a crash.
diff --git a/dlls/ole32/tests/compobj.c b/dlls/ole32/tests/compobj.c
index 24d790a..b2aaa22 100644
--- a/dlls/ole32/tests/compobj.c
+++ b/dlls/ole32/tests/compobj.c
@@ -944,7 +944,9 @@
 
     ok(is_module_loaded("urlmon.dll"), "urlmon.dll should be loaded\n");
 
-    IUnknown_Release(pUnk);
+    ok(pUnk != NULL, "Expected a valid pointer\n");
+    if (pUnk)
+        IUnknown_Release(pUnk);
 
     ok(is_module_loaded("urlmon.dll"), "urlmon.dll should be loaded\n");