--- a/devtools/client/inspector/rules/rules.js
+++ b/devtools/client/inspector/rules/rules.js
@@ -1624,16 +1624,17 @@ function RuleViewTool(inspector, window)
   this.inspector = inspector;
   this.document = window.document;
 
   this.view = new CssRuleView(this.inspector, this.document);
 
   this.clearUserProperties = this.clearUserProperties.bind(this);
   this.refresh = this.refresh.bind(this);
   this.onPanelSelected = this.onPanelSelected.bind(this);
+  this.onDetachedFront = this.onDetachedFront.bind(this);
   this.onSelected = this.onSelected.bind(this);
   this.onViewRefreshed = this.onViewRefreshed.bind(this);
 
   this.view.on("ruleview-refreshed", this.onViewRefreshed);
   this.inspector.selection.on("detached-front", this.onDetachedFront);
   this.inspector.selection.on("new-node-front", this.onSelected);
   this.inspector.selection.on("pseudoclass", this.refresh);
   this.inspector.target.on("navigate", this.clearUserProperties);