diff --git a/implementations/javascript/package.json b/implementations/javascript/package.json
index d947e1a..69939aa 100644
--- a/implementations/javascript/package.json
+++ b/implementations/javascript/package.json
@@ -26,7 +26,7 @@
     "prepare": "npx tsc && npx rollup -c",
     "rollupwatch": "npx rollup -c -w",
     "test": "npx jest",
-    "testwatch": "npx jest -w",
+    "testwatch": "npx jest --watch",
     "veryclean": "npm run clean && rm -rf node_modules",
     "watch": "npx tsc -w"
   },