diff --git a/src/services/sync.service.ts b/src/services/sync.service.ts
index 25ab7341..9f698532 100644
--- a/src/services/sync.service.ts
+++ b/src/services/sync.service.ts
@@ -104,7 +104,7 @@ export class SyncService {
     }
 
     private filterUnsupportedUsers(users: UserEntry[]): UserEntry[] {
-        return users == null ? null : users.filter(u => u.email == null || u.email.length <= 50);
+        return users == null ? null : users.filter(u => u.email?.length <= 50);
     }
 
     private flattenUsersToGroups(levelGroups: GroupEntry[], allGroups: GroupEntry[]): Set<string> {