diff --git a/devtools/client/aboutdebugging/test/browser_addons_debug_info.js b/devtools/client/aboutdebugging/test/browser_addons_debug_info.js
index af2d5960a688..a375ce29ae6c 100644
--- a/devtools/client/aboutdebugging/test/browser_addons_debug_info.js
+++ b/devtools/client/aboutdebugging/test/browser_addons_debug_info.js
@@ -71,7 +71,7 @@ add_task(function* testTemporaryWebExtension() {
 
   let addons = document.querySelectorAll("#temporary-extensions .addon-target-container");
   // Assuming that our temporary add-on is now at the top.
-  let container = addons[addons.length-1];
+  let container = addons[addons.length - 1];
   let addonId = container.dataset.addonId;
 
   let temporaryID = container.querySelector(".temporary-id-url");