diff --git a/src/core/controllers/InstallerController.php b/src/core/controllers/InstallerController.php
index a683446ddde25f2942daa8a5de94f225577f2056..1f02d050f0c8432c12f9fd7ca1a75ec64c8f2873 100644
--- a/src/core/controllers/InstallerController.php
+++ b/src/core/controllers/InstallerController.php
@@ -538,6 +538,11 @@ class InstallerController
         DatabasePDO::reset();
         new DatabasePDO(['customId' => $body['customId']]);
 
+        $userAlreadyExists = UserModel::getByLogin(['login' => strtolower($body['login']), 'select' => 1]);
+        if (!empty($userAlreadyExists)) {
+            return $response->withStatus(400)->withJson(['errors' => 'User already exists', 'lang' => 'alreadyExist']);
+        }
+
         UserModel::create([
             'user' => [
                 'userId'        => $body['login'],
diff --git a/test/unitTests/app/user/UserControllerTest.php b/test/unitTests/app/user/UserControllerTest.php
index 469026ad2859c67db46ffb36ba64fdd87f0d2fdf..9a71fb2f0f85e5454bbeb5c6d853da7298564d5e 100755
--- a/test/unitTests/app/user/UserControllerTest.php
+++ b/test/unitTests/app/user/UserControllerTest.php
@@ -290,7 +290,7 @@ class UserControllerTest extends TestCase
         $response     = $userController->update($fullRequest, new \Slim\Http\Response(), ['id' => self::$id]);
         $this->assertSame(400, $response->getStatusCode());
         $responseBody = json_decode((string)$response->getBody(), true);
-        $this->assertSame('Bad Request', $responseBody['errors']);
+        $this->assertSame('Body phone is not correct', $responseBody['errors']);
     }
 
     public function testAddGroup()