diff --git a/make/topdir.mk b/make/topdir.mk
index 06d10ed5..e29e9c1f 100644
--- a/make/topdir.mk
+++ b/make/topdir.mk
@@ -93,5 +93,5 @@ git-init:
 	git commit -m "initial checkin of $(RPM_VERSION)"
 
 scratch-%:
-	sh $(MOD_SCRIPT_DIR)/build.sh $* $(PROJECT)
+	sh $(MOD_SCRIPT_DIR)/build.py $* $(PROJECT)