diff --git a/src/_locales/en/messages.json b/src/_locales/en/messages.json
index de6f351..d542386 100644
--- a/src/_locales/en/messages.json
+++ b/src/_locales/en/messages.json
@@ -142,5 +142,9 @@
   "inject_ccdarktheme_helper": {
     "message": "Switch theme",
     "description": "Tooltip for the dark mode switch."
+  },
+  "inject_extension_badge_helper": {
+    "message": "Added by $1",
+    "description": "Tooltip for the extension badge, which appears next to components injected by the extension."
   }
 }