diff --git a/full/src/test/java/de/ids_mannheim/korap/authentication/LdapAuth3Test.java b/full/src/test/java/de/ids_mannheim/korap/authentication/LdapAuth3Test.java
index 65322d9..de8b9b1 100644
--- a/full/src/test/java/de/ids_mannheim/korap/authentication/LdapAuth3Test.java
+++ b/full/src/test/java/de/ids_mannheim/korap/authentication/LdapAuth3Test.java
@@ -154,6 +154,17 @@
         assertEquals("peter@example.org", LdapAuth3.getEmail("testuser2", TEST_LDAPS_CONF));
         assertEquals(null, LdapAuth3.getEmail("non-exsting", TEST_LDAPS_CONF));
     }
+    
+    @Test
+    public void gettingUsernameForEmail() throws LDAPException {
+        assertEquals("idsTestUser", LdapAuth3.getUsername("testuser@example.com", TEST_LDAP_CONF));
+        assertEquals("testuser2", LdapAuth3.getUsername("peter@example.org", TEST_LDAPS_CONF));
+        assertEquals(null, LdapAuth3.getUsername("non-exsting", TEST_LDAPS_CONF));
+
+        assertEquals("testuser2", LdapAuth3.getUsername("testUser2", TEST_LDAPS_CONF));
+        // login with uid, get idsC2Profile username
+        assertEquals("idsTestUser", LdapAuth3.getUsername("testUser", TEST_LDAPS_CONF));
+    }
 
     @Test
     public void gettingMailAttributeForNotRegisteredUserWorks() throws LDAPException {
diff --git a/full/src/test/resources/test-ldap-users.ldif b/full/src/test/resources/test-ldap-users.ldif
index b35a919..0b92701 100644
--- a/full/src/test/resources/test-ldap-users.ldif
+++ b/full/src/test/resources/test-ldap-users.ldif
@@ -19,6 +19,7 @@
 extraProfile: testuser123
 extraPassword: password
 uid: testuser
+idsC2Profile: idsTestUser
 
 dn: uid=test,ou=people,dc=example,dc=com
 cn: Peter Test