diff --git a/packages/firefox-config.xml b/packages/firefox-config.xml
index 45bb30e..b93d9e9 100644
--- a/packages/firefox-config.xml
+++ b/packages/firefox-config.xml
@@ -23,6 +23,8 @@
 
         <upgrade include="install" />
 
+        <downgrade include="install" />
+
         <remove cmd='%COMSPEC% /C del /F "%PROG%\defaults\pref\autoconf.js"' />
         <remove cmd='%COMSPEC% /C del /F "%PROG%\override.ini"' />
         <remove cmd='%COMSPEC% /C del /F "%PROG%\firefox.cfg"' />