diff --git a/application/controllers/system/Login.php b/application/controllers/system/Login.php
index 8593a766a..293a25552 100644
--- a/application/controllers/system/Login.php
+++ b/application/controllers/system/Login.php
@@ -55,14 +55,7 @@ class Login extends FHC_Controller
 		$this->load->library('AuthLib');
 
 		$loginAS = $this->authlib->loginASByUID($uid);
-		if (isSuccess($loginAS))
-		{
-			$this->outputJsonSuccess(true); // obtained!
-		}
-		else
-		{
-			$this->outputJsonSuccess(getCode($loginAS)); // returns the error code
-		}
+		$this->outputJson($loginAS); // returns the error code
 	}
 
 	/**
diff --git a/application/libraries/AuthLib.php b/application/libraries/AuthLib.php
index 0558144a1..fe6261106 100644
--- a/application/libraries/AuthLib.php
+++ b/application/libraries/AuthLib.php
@@ -80,6 +80,10 @@ class AuthLib
 						setSessionElement(self::SESSION_NAME, self::SESSION_AUTH_OBJ, getData($loginAS));
 					}
 				}
+				else
+				{
+					$loginAS = error('It is not allowed to switch to this user', AUTH_NOT_AUTHENTICATED); // not authenticated by default
+				}
 			}
 			else
 			{