diff --git a/gen-npm-pkg.sh b/gen-npm-pkg.sh
index ec83aa5..b1f4ab1 100644
--- a/gen-npm-pkg.sh
+++ b/gen-npm-pkg.sh
@@ -56,7 +56,7 @@ for PACKAGE_DIR in "$BASE_DIR"/*; do
     # Step 2: Run Rollup to create CJS format
     CJS_FILE="${ESM_FILE%-esm.js}-cjs.js"
     echo "Creating CJS format for $PACKAGE_NAME..."
-    rollup "$ESM_FILE" --file "$CJS_FILE" --format cjs
+    npx rollup "$ESM_FILE" --file "$CJS_FILE" --format cjs
 
     # Add the package export entry to the main package.json
     cat <<EOF >> "$PACKAGE_JSON"