diff --git a/appveyor.yml b/appveyor.yml
index 0ff1bba80b..1cfdf384bc 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -10,5 +10,5 @@ build_script:
   - cd csources
   - build64.bat
   - cd ..
-  - bin\nim koch
+  - bin\nim c koch
   - koch boot