diff --git a/devtools/client/netmonitor/test/browser_net_filter-autocomplete.js b/devtools/client/netmonitor/test/browser_net_filter-autocomplete.js
index 851ecef15718..126dab8cb8b0 100644
--- a/devtools/client/netmonitor/test/browser_net_filter-autocomplete.js
+++ b/devtools/client/netmonitor/test/browser_net_filter-autocomplete.js
@@ -51,7 +51,7 @@ add_task(async function() {
   await waitNetwork;
 
   EventUtils.synthesizeMouseAtCenter(
-    document.querySelector(".devtools-filterinput"), {}, window);
+    document.querySelector(".devtools-filterinput"), {}, document.defaultView);
   // Empty Mouse click should keep autocomplete hidden
   ok(!document.querySelector(".devtools-autocomplete-popup"),
     "Autocomplete Popup still hidden");