diff --git a/lib/Froxlor/Api/Commands/Ftps.php b/lib/Froxlor/Api/Commands/Ftps.php
index 55632b71..68f1acad 100644
--- a/lib/Froxlor/Api/Commands/Ftps.php
+++ b/lib/Froxlor/Api/Commands/Ftps.php
@@ -541,6 +541,9 @@ class Ftps extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEntit
 				"username" => $customer_data['loginname']
 			);
 			Database::pexecute($stmt, $params, true, true);
+		} else {
+			// do not allow removing default ftp-account
+			\Froxlor\UI\Response::standard_error('ftp_cantdeletemainaccount', '', true);
 		}
 
 		// remove all quotatallies
diff --git a/tests/Ftps/FtpsTest.php b/tests/Ftps/FtpsTest.php
index 32e7f65b..75d739d5 100644
--- a/tests/Ftps/FtpsTest.php
+++ b/tests/Ftps/FtpsTest.php
@@ -277,4 +277,21 @@ class FtpsTest extends TestCase
 		$result = json_decode($json_result, true)['data'];
 		$this->assertEquals('test1ftp2', $result['username']);
 	}
+
+	public function testCustomerFtpsDeleteDefaultUser()
+	{
+		global $admin_userdata;
+
+		// get customer
+		$json_result = Customers::getLocal($admin_userdata, array(
+			'loginname' => 'test1'
+		))->get();
+		$customer_userdata = json_decode($json_result, true)['data'];
+		$data = [
+			'username' => 'test1'
+		];
+		$this->expectExceptionCode(400);
+		$this->expectExceptionMessage('You cannot delete your main FTP account');
+		Ftps::getLocal($customer_userdata, $data)->delete();
+	}
 }