diff --git a/caravel/models.py b/caravel/models.py
index 725f7d22da0c5..fe2b22fc92f93 100644
--- a/caravel/models.py
+++ b/caravel/models.py
@@ -1951,9 +1951,10 @@ def recursive_get_fields(_conf):
             client.timeseries(**qry)
         if len(groupby) == 1:
             if not timeseries_limit:
-                timeseries_limit = 10000
+                timeseries_limit = 1000
+
             qry['threshold'] = timeseries_limit
-            qry['dimension'] = qry.get('dimensions')[0]
+            qry['dimension'] = list(qry.get('dimensions'))[0]
             del qry['dimensions']
             qry['metric'] = list(qry['aggregations'].keys())[0]
             client.topn(**qry)