diff --git a/src/apps.json b/src/apps.json
index 5fe2eea48..119509f74 100644
--- a/src/apps.json
+++ b/src/apps.json
@@ -3413,6 +3413,7 @@
         4
       ],
       "icon": "GitBook.png",
+      "url": "^https?://[^/]+\\.gitbook\\.io/",
       "meta": {
         "generator": "GitBook(?:.([\\d.]+))?\\;version:\\1"
       },