diff --git a/manifest.json b/manifest.json
index 34a2fd6e..5cd7006c 100644
--- a/manifest.json
+++ b/manifest.json
@@ -5,6 +5,12 @@
   "description": "__MSG_description__",
   "homepage_url": "https://add0n.com/stylus.html",
   "manifest_version": 2,
+  "applications": {
+    "gecko": {
+      "id": "{a9449967-86c7-4d0e-8285-322cef7c40f2}",
+      "strict_min_version": "42.0"
+    }
+  },
   "icons": {
     "16": "/images/icon/16.png",
     "32": "/images/icon/32.png",