diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index 797d7ae..be298e1 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -27,4 +27,4 @@ jobs:
         run: npm install --global vercel@latest
       - name: Deploy to Vercel
         id: deploy
-        run: echo "url=$(vercel ${{ inputs.isProd && '--prod' }} --yes --token=${{ secrets.VERCEL_TOKEN }})" >> "$GITHUB_OUTPUT"
+        run: echo "url=$(vercel ${{ inputs.isProd == true && '--prod' || '' }} --yes --token=${{ secrets.VERCEL_TOKEN }})" >> "$GITHUB_OUTPUT"