diff --git a/src/new_build.sh b/src/new_build.sh
index 2f639cb..ddc0c5a 100755
--- a/src/new_build.sh
+++ b/src/new_build.sh
@@ -81,6 +81,7 @@ do_cleanup() {
     else
       cd "$source_dir"
       (set +eu ; mka "${jobs_arg[@]}" clean) &>> "$DEBUG_LOG"
+      rm -rf vendor/* || true
     fi
   fi
 }