diff --git a/browser/base/content/test/performance/browser_startup_mainthreadio.js b/browser/base/content/test/performance/browser_startup_mainthreadio.js
index f21f60803832..2d9f17fbb980 100644
--- a/browser/base/content/test/performance/browser_startup_mainthreadio.js
+++ b/browser/base/content/test/performance/browser_startup_mainthreadio.js
@@ -231,6 +231,11 @@ const startupPhases = {
       condition: WIN,
       stat: 1,
     },
+    {
+      path: "XCurProcD:blocklist.xml",
+      condition: WIN,
+      stat: 1,
+    },
     {
       // bug 1534745
       path: "ProfD:cookies.sqlite-journal",
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 849dfa5bcb88..b939110b682a 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2305,8 +2305,6 @@ pref("extensions.blocklist.enabled", true);
 // OneCRL freshness checking depends on this value, so if you change it,
 // please also update security.onecrl.maximum_staleness_in_seconds.
 pref("extensions.blocklist.interval", 86400);
-// Whether to use the XML backend (true) or the remotesettings one (false).
-pref("extensions.blocklist.useXML", false);
 // Required blocklist freshness for OneCRL OCSP bypass
 // (default is 1.25x extensions.blocklist.interval, or 30 hours)
 pref("security.onecrl.maximum_staleness_in_seconds", 108000);
diff --git a/toolkit/mozapps/extensions/Blocklist.jsm b/toolkit/mozapps/extensions/Blocklist.jsm
index e6d234996299..2f1d00aec9c7 100644
--- a/toolkit/mozapps/extensions/Blocklist.jsm
+++ b/toolkit/mozapps/extensions/Blocklist.jsm
@@ -3239,7 +3239,7 @@ XPCOMUtils.defineLazyPreferenceGetter(
   Blocklist,
   "useXML",
   "extensions.blocklist.useXML",
-  false,
+  true,
   () => Blocklist.onUpdateImplementation(true)
 );