diff --git a/superset/utils.py b/superset/utils.py
index 61d5cb63dba34..ed9968ce8d0ea 100644
--- a/superset/utils.py
+++ b/superset/utils.py
@@ -737,7 +737,7 @@ def get_filter_key(f):
             return f['col'] + '__' + f['op']
         existing_filters = {}
         for existing in form_data['filters']:
-            if existing['col'] is not None:
+            if existing['col'] is not None and existing['val'] is not None:
                 existing_filters[get_filter_key(existing)] = existing['val']
         for filtr in form_data['extra_filters']:
             # Pull out time filters/options and merge into form data