diff --git a/.gitignore b/.gitignore
index 3bf1301ec..429873229 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,9 @@ __pycache__/
 # C extensions
 *.so
 
+# Nodejs
+node_modules/
+
 # Distribution / packaging
 .Python
 env/
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 000000000..8bfa7ed8f
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,24 @@
+{
+  "requires": true,
+  "lockfileVersion": 1,
+  "dependencies": {
+    "node": {
+      "version": "8.3.0",
+      "resolved": "https://registry.npmjs.org/node/-/node-8.3.0.tgz",
+      "integrity": "sha512-RU3iQgXeDBU45dv6BrfDrgTyUjJk1yorN64l0sce+E+2pZzFbRbBicPMBD/hWjo0GSMnA5a+RwFtWwHNDlojaw==",
+      "requires": {
+        "node-bin-setup": "1.0.6"
+      }
+    },
+    "node-bin-setup": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/node-bin-setup/-/node-bin-setup-1.0.6.tgz",
+      "integrity": "sha512-uPIxXNis1CRbv1DwqAxkgBk5NFV3s7cMN/Gf556jSw6jBvV7ca4F9lRL/8cALcZecRibeqU+5dFYqFFmzv5a0Q=="
+    },
+    "nodejs": {
+      "version": "0.0.0",
+      "resolved": "https://registry.npmjs.org/nodejs/-/nodejs-0.0.0.tgz",
+      "integrity": "sha1-RyL6LhisTrc6Qq4W0B41hKErdTE="
+    }
+  }
+}
diff --git a/sapl/base/forms.py b/sapl/base/forms.py
index 992ce558b..7e64c33cd 100644
--- a/sapl/base/forms.py
+++ b/sapl/base/forms.py
@@ -231,7 +231,7 @@ class AutorForm(ModelForm):
         if 'status_user' in self.Meta.fields:
             if self.instance.pk and self.instance.user_id:
                 if getattr(
-                        self.instance.user.username,
+                        self.instance.user,
                         get_user_model().USERNAME_FIELD) != cd['username']:
                     if 'status_user' not in cd or not cd['status_user']:
                         raise ValidationError(