diff --git a/app/lib/App/Teamtable/Team.php b/app/lib/App/Teamtable/Team.php
index 91327fa..81e9216 100644
--- a/app/lib/App/Teamtable/Team.php
+++ b/app/lib/App/Teamtable/Team.php
@@ -21,7 +21,7 @@ class Team
     /**
      * PHP by default does not include multi byte functions. Therefore we use this
      */
-    private function count_characters(string $string)
+    private function count_characters(string $string): int
     {
         return count(preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY));
     }