diff --git a/mayan/apps/common/forms.py b/mayan/apps/common/forms.py
index 7703714a24..bac0634ce9 100644
--- a/mayan/apps/common/forms.py
+++ b/mayan/apps/common/forms.py
@@ -164,8 +164,8 @@ class EmailAuthenticationForm(forms.Form):
         return self.cleaned_data
 
     def check_for_test_cookie(self):
-        warnings.warn("check_for_test_cookie is deprecated; ensure your login "
-                "view is CSRF-protected.", DeprecationWarning)
+        warnings.warn('check_for_test_cookie is deprecated; ensure your login '
+                'view is CSRF-protected.', DeprecationWarning)
 
     def get_user_id(self):
         if self.user_cache: