diff --git a/remote/shared/RecommendedPreferences.sys.mjs b/remote/shared/RecommendedPreferences.sys.mjs
index 4c66ba4543c1..236a7f0e6645 100644
--- a/remote/shared/RecommendedPreferences.sys.mjs
+++ b/remote/shared/RecommendedPreferences.sys.mjs
@@ -265,10 +265,7 @@ const COMMON_PREFERENCES = new Map([
     "http://%(server)s/extensions-dummy/blocklistItemURL",
   ],
   ["extensions.hotfix.url", "http://%(server)s/extensions-dummy/hotfixURL"],
-  [
-    "extensions.systemAddon.update.url",
-    "http://%(server)s/dummy-system-addons.xml",
-  ],
+  ["extensions.systemAddon.update.enabled", false],
   [
     "extensions.update.background.url",
     "http://%(server)s/extensions-dummy/updateBackgroundURL",
diff --git a/testing/marionette/client/marionette_driver/geckoinstance.py b/testing/marionette/client/marionette_driver/geckoinstance.py
index 1844f5e71da4..02b61e5ce1ec 100644
--- a/testing/marionette/client/marionette_driver/geckoinstance.py
+++ b/testing/marionette/client/marionette_driver/geckoinstance.py
@@ -107,7 +107,7 @@ class GeckoInstance(object):
         ),
         "extensions.blocklist.itemURL": "http://%(server)s/extensions-dummy/blocklistItemURL",
         "extensions.hotfix.url": "http://%(server)s/extensions-dummy/hotfixURL",
-        "extensions.systemAddon.update.url": "http://%(server)s/dummy-system-addons.xml",
+        "extensions.systemAddon.update.enabled": False,
         "extensions.update.background.url": (
             "http://%(server)s/extensions-dummy/updateBackgroundURL"
         ),