diff --git a/src/RunCommand.php b/src/RunCommand.php
index 38bf6b13..799d57be 100644
--- a/src/RunCommand.php
+++ b/src/RunCommand.php
@@ -119,6 +119,10 @@ private function uploadImagePreconditionsOK($configFritz, $configPhonebook)
             return "ERROR: config.php missing phonebook/imagepath setting.".PHP_EOL.
                     "       Image upload not possible (remove -i switch).";
         }
+        if ($configFritz['user'] == 'dslf-conf') {
+            return "ERROR: TR-064 default user dslf-conf has no permission for ftp access.".PHP_EOL.
+                    "       Image upload not possible (remove -i switch).";
+        }
         return true;
     }