diff --git a/reactos/dll/win32/kernel32/client/actctx.c b/reactos/dll/win32/kernel32/client/actctx.c
index abe1b40132c..3271415311d 100644
--- a/reactos/dll/win32/kernel32/client/actctx.c
+++ b/reactos/dll/win32/kernel32/client/actctx.c
@@ -386,6 +386,8 @@ QueryActCtxW(IN DWORD dwFlags,
         case QUERY_ACTCTX_FLAG_ACTCTX_IS_ADDRESS:
             NativeFlags = RTL_QUERY_ACTIVATION_CONTEXT_FLAG_IS_ADDRESS;
             break;
+        case 0:
+            break;
 
         /* More than one flag is set... */
         default: