diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 3831d19c6d..7229f14485 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -23,7 +23,7 @@ pref("keyword.enabled", false);
 pref("general.useragent.locale", "chrome://global/locale/intl.properties");
 pref("general.useragent.compatMode.gecko", false);
 pref("general.useragent.compatMode.firefox", false);
-pref("general.useragent.compatMode.version", "52.9");
+pref("general.useragent.compatMode.version", "60.9");
 pref("general.useragent.appVersionIsBuildID", false);
 
 // This pref exists only for testing purposes. In order to disable all