diff --git a/src/main/java/de/cantorgymnasium/auth/provider/user/mailcowUser.java b/src/main/java/de/cantorgymnasium/auth/provider/user/mailcowUser.java
index 5d8b50b..e851b53 100644
--- a/src/main/java/de/cantorgymnasium/auth/provider/user/mailcowUser.java
+++ b/src/main/java/de/cantorgymnasium/auth/provider/user/mailcowUser.java
@@ -65,7 +65,7 @@ class mailcowUser extends AbstractUserAdapter {
         MultivaluedHashMap<String, String> attributes = new MultivaluedHashMap<>();
         attributes.add(UserModel.USERNAME, getUsername());
         attributes.add(UserModel.EMAIL, getEmail());
-        attributes.add(UserModel.EMAIL_VERIFIED, "true");
+        attributes.add(UserModel.EMAIL_VERIFIED, Boolean.toString(true));
         attributes.add(UserModel.FIRST_NAME, getFirstName());
         attributes.add(UserModel.LAST_NAME, getLastName());
         attributes.add("domain", getDomain());