diff --git a/ckan/controllers/api.py b/ckan/controllers/api.py
index 1000b673720..2a739266db0 100644
--- a/ckan/controllers/api.py
+++ b/ckan/controllers/api.py
@@ -207,7 +207,7 @@ def action(self, logic_function):
             return self._finish(409, return_dict, content_type='json')
         return self._finish_ok(return_dict)
 
-    def _get_action_from_map(action_map, register, subregister):
+    def _get_action_from_map(self, action_map, register, subregister):
         # Helper function to get the action function specified in the action map
 
         assert (register != 'package') # these should all have been redirected!