diff --git a/src/Helpers/UsersHelper.cs b/src/Helpers/UsersHelper.cs
index 7f16c4e..41edf60 100644
--- a/src/Helpers/UsersHelper.cs
+++ b/src/Helpers/UsersHelper.cs
@@ -11,7 +11,7 @@ public static partial class UsersHelper
             throw new ArgumentException("Given name and surname must not be empty.");
 
         string combined = (surname + givenName).ToLowerInvariant();
-
+        combined = combined.Replace("ä", "ae").Replace("ö", "oe").Replace("ü", "ue");
         // Normalize to decompose accents (e.g., é -> e +  ́)
         string normalized = combined.Normalize(NormalizationForm.FormD);