diff --git a/service/src/main/java/lcsb/mapviewer/services/impl/LdapService.java b/service/src/main/java/lcsb/mapviewer/services/impl/LdapService.java
index 589602f8c389566033f5b7d7d81db7803f0222e2..ba720f8779e68ccd923e9442c58abb88e9943a42 100644
--- a/service/src/main/java/lcsb/mapviewer/services/impl/LdapService.java
+++ b/service/src/main/java/lcsb/mapviewer/services/impl/LdapService.java
@@ -146,11 +146,11 @@ public class LdapService implements ILdapService {
           .getConfigurationValue(ConfigurationElementType.LDAP_LAST_NAME_ATTRIBUTE);
       String emailAttribute = configurationService.getConfigurationValue(ConfigurationElementType.LDAP_EMAIL_ATTRIBUTE);
 
-      Filter f1 = createLoginFilter(login);
+      Filter loginFilter = createLoginFilter(login);
       Filter f2 = createObjectClassFilter();
       Filter f3 = createAttributeFilter();
 
-      Filter filter = Filter.createANDFilter(f1, f2, f3);
+      Filter filter = Filter.createANDFilter(loginFilter, f2, f3);
       SearchResult searchResult = connection.search(baseDn, SearchScope.SUB, filter);
 
       for (SearchResultEntry entry : searchResult.getSearchEntries()) {
@@ -186,6 +186,10 @@ public class LdapService implements ILdapService {
 
         return result;
       }
+      searchResult = connection.search(baseDn, SearchScope.SUB, loginFilter);
+      if (searchResult.getSearchEntries().size() > 0) {
+        logger.debug("User '" + login + "' exists, but was filtered out [filter=" + filter.toString() + "]");
+      }
       return null;
     } finally {
       connection.close();