diff --git a/core/misc/states.js b/core/misc/states.js
index 75ee01d..c85536f 100644
--- a/core/misc/states.js
+++ b/core/misc/states.js
@@ -163,7 +163,7 @@ states.Dependent.prototype = {
    */
   update: function (selector, state, value) {
     // Only act when the 'new' value is actually new.
-    if (value !== this.values[selector][state.name]) {
+    if (value !== this.values[selector][state.name] || value === null) {
       this.values[selector][state.name] = value;
       this.reevaluate();
     }