diff --git a/devtools/client/framework/toolbox.js b/devtools/client/framework/toolbox.js
index 9b9fa66330..fae3602622 100644
--- a/devtools/client/framework/toolbox.js
+++ b/devtools/client/framework/toolbox.js
@@ -2182,14 +2182,16 @@ Toolbox.prototype = {
         .then(() => {
           this._removeHostListeners();
 
-          // `location` may already be null if the toolbox document is already
-          // in process of destruction. Otherwise if it is still around, ensure
-          // releasing toolbox document and triggering cleanup thanks to unload
-          // event. We do that precisely here, before nullifying the target as
-          // various cleanup code depends on the target attribute to be still
-          // defined.
-          if (win.location) {
+          // `location` may already be invalid if the toolbox document is
+          // already in process of destruction. Otherwise if it is still
+          // around, ensure releasing toolbox document and triggering cleanup
+          // thanks to unload event. We do that precisely here, before
+          // nullifying the target as various cleanup code depends on the
+          // target attribute to be still defined.
+          try {
             win.location.replace("about:blank");
+          } catch (e) {
+            // Do nothing.
           }
 
           // Targets need to be notified that the toolbox is being torn down.