diff --git a/apps/OpenSign/package.json b/apps/OpenSign/package.json
index 0c3d512c4..77dce998b 100644
--- a/apps/OpenSign/package.json
+++ b/apps/OpenSign/package.json
@@ -118,7 +118,7 @@
     "prettier": "^3.7.4",
     "pretty-quick": "^4.2.2",
     "rollup-plugin-node-polyfills": "^0.2.1",
-    "tailwindcss": "^3.4.19",
+    "tailwindcss": "^4.1.18",
     "tmp": "^0.2.5",
     "vite": "^7.3.0",
     "vite-plugin-svgr": "^4.5.0",