diff --git a/user.js b/user.js
index d03f494..3061845 100644
--- a/user.js
+++ b/user.js
@@ -542,8 +542,9 @@ user_pref("dom.disable_window_move_resize", true);
 
 /*** [SECTION 2600]: MISCELLANEOUS ***/
 user_pref("_user.js.parrot", "2600 syntax error: the parrot's run down the curtain!");
-/* 2603: remove temp files opened with an external application
- * [1] https://bugzilla.mozilla.org/302433 ***/
+/* 2603: remove temp files opened from non-PB windows with an external application
+ * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=302433,1738574 ***/
+user_pref("browser.download.start_downloads_in_tmp_dir", true); // [FF102+]
 user_pref("browser.helperApps.deleteTempFileOnExit", true);
 /* 2606: disable UITour backend so there is no chance that a remote page can use it ***/
 user_pref("browser.uitour.enabled", false);