diff --git a/SoObjects/SOGo/SOGoUserFolder.m b/SoObjects/SOGo/SOGoUserFolder.m
index ba8414b81..2a44128e8 100644
--- a/SoObjects/SOGo/SOGoUserFolder.m
+++ b/SoObjects/SOGo/SOGoUserFolder.m
@@ -427,7 +427,8 @@
         {
           currentUser = [users objectAtIndex: i];
           field = [currentUser objectForKey: @"c_uid"];
-          if (enableDomainBasedUID)
+          if (enableDomainBasedUID &&
+              [field rangeOfString: @"@"].location == NSNotFound)
             field = [NSString stringWithFormat: @"%@@%@", field, domain];
           if (![field isEqualToString: login])
             {
diff --git a/SoObjects/SOGo/SOGoUserManager.m b/SoObjects/SOGo/SOGoUserManager.m
index 125ca3fcc..fd8105c0b 100644
--- a/SoObjects/SOGo/SOGoUserManager.m
+++ b/SoObjects/SOGo/SOGoUserManager.m
@@ -622,7 +622,8 @@ static Class NSNullK;
       // internal cache.
       [currentUser setObject: [newPassword asSHA1String] forKey: @"password"];
       sd = [SOGoSystemDefaults sharedSystemDefaults];
-      if ([sd enableDomainBasedUID])
+      if ([sd enableDomainBasedUID] &&
+          [login rangeOfString: @"@"].location == NSNotFound)
         userLogin = [NSString stringWithFormat: @"%@@%@", login, domain];
       else
         userLogin = login;
diff --git a/UI/MainUI/SOGoRootPage.m b/UI/MainUI/SOGoRootPage.m
index df3e944b1..dc9712e88 100644
--- a/UI/MainUI/SOGoRootPage.m
+++ b/UI/MainUI/SOGoRootPage.m
@@ -228,7 +228,8 @@
       if ([domain isNotNull])
         {
           sd = [SOGoSystemDefaults sharedSystemDefaults];
-          if ([sd enableDomainBasedUID])
+          if ([sd enableDomainBasedUID] &&
+              [username rangeOfString: @"@"].location == NSNotFound)
             username = [NSString stringWithFormat: @"%@@%@", username, domain];
         }
 
@@ -587,7 +588,8 @@
       if ([domain isNotNull])
         {
           sd = [SOGoSystemDefaults sharedSystemDefaults];
-          if ([sd enableDomainBasedUID])
+          if ([sd enableDomainBasedUID] &&
+              [username rangeOfString: @"@"].location == NSNotFound)
             username = [NSString stringWithFormat: @"%@@%@", username, domain];
         }