diff --git a/lib/support/flattenMessage.js b/lib/support/flattenMessage.js
index 322a44b0e..2091e4bac 100644
--- a/lib/support/flattenMessage.js
+++ b/lib/support/flattenMessage.js
@@ -27,12 +27,12 @@ module.exports = {
       path = joinNonEmpty([path, toSafeKey(flattenQueryParams(url.query))], '_');
     }
 
-    let keys = [
+    const keys = [
       toSafeKey(url.hostname),
       path
     ];
 
-    return keys.filter((key) => (key && key.length)).join('.');
+    return joinNonEmpty(keys, '.');
   },
 
   flattenMessageData(message) {