diff --git a/ckan/controllers/api.py b/ckan/controllers/api.py
index e114253f919..23aec691ced 100644
--- a/ckan/controllers/api.py
+++ b/ckan/controllers/api.py
@@ -730,7 +730,8 @@ def dataset_autocomplete(self):
         return self._finish_ok(resultSet)
 
     def tag_autocomplete(self):
-        q = request.params.get('incomplete', '')
+        q = request.str_params.get('incomplete', '')
+        q = unicode(urllib.unquote(q), 'utf-8')
         limit = request.params.get('limit', 10)
         tag_names = []
         if q: