diff --git a/browser/devtools/framework/sidebar.js b/browser/devtools/framework/sidebar.js
index e312db4512d..af41f4d47ca 100644
--- a/browser/devtools/framework/sidebar.js
+++ b/browser/devtools/framework/sidebar.js
@@ -148,6 +148,11 @@ ToolSidebar.prototype = {
    */
   handleEvent: function ToolSidebar_eventHandler(event) {
     if (event.type == "select") {
+      if (this._currentTool == this.getCurrentTabID()) {
+        // Tool hasn't changed.
+        return;
+      }
+
       let previousTool = this._currentTool;
       this._currentTool = this.getCurrentTabID();
       if (previousTool) {