diff --git a/caravel/assets/javascripts/explore.js b/caravel/assets/javascripts/explore.js
index 55c71b90e0c81..fe64c85e59fd9 100644
--- a/caravel/assets/javascripts/explore.js
+++ b/caravel/assets/javascripts/explore.js
@@ -237,7 +237,8 @@ function initExploreView() {
   function set_filters() {
     for (var i = 1; i < 10; i++) {
       var eq = px.getParam("flt_eq_" + i);
-      if (eq !== '') {
+      var col = px.getParam("flt_col_" + i);
+      if (eq !== '' && col !== '') {
         add_filter(i);
       }
     }
diff --git a/caravel/forms.py b/caravel/forms.py
index fa9227d43c7ce..d7c77439ce69c 100644
--- a/caravel/forms.py
+++ b/caravel/forms.py
@@ -52,7 +52,7 @@ def iter_choices(self):
             d[value] = (value, label, selected)
         if self.data:
             for value in self.data:
-                if value:
+                if value and value in d:
                     yield d.pop(value)
         while d:
             yield d.popitem(last=False)[1]