diff --git a/package.json b/package.json
index f435dc5..92e14d0 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
     "build": "ts-node -T build.ts --firefox --chrome",
     "build:firefox": "ts-node -T build.ts --firefox",
     "build:chrome": "ts-node -T build.ts --chrome",
-    "run:firefox": "web-ext run -s dist-firefox",
+    "run:firefox": "web-ext run -s dist-firefox --firefox=/home/yuki/opt/firefox/firefox",
     "run:chrome": "web-ext run -s dist-chrome -t chromium",
     "package:firefox": "web-ext build -s dist-firefox --overwrite-dest",
     "lint": "eslint --max-warnings=0 . && prettier --check .",