diff --git a/pkgs/firefox-nightly/version.json b/pkgs/firefox-nightly/version.json
index 8e3c1b6fd..9c94d2761 100644
--- a/pkgs/firefox-nightly/version.json
+++ b/pkgs/firefox-nightly/version.json
@@ -1,5 +1,5 @@
 {
-  "version": "135.0a1",
-  "rev": "e8452cb27c317626557cf1583a9c98ad4926bd60",
-  "hash": "sha256-W84rNavAiRvfdN1UB2Qsr9QafVCMsnuy0FZMwwWq3g8="
+  "version": "133.0a1",
+  "rev": "8f17db3a71db2ee2ca59466130ca0a67ec65f0b9",
+  "hash": "sha256-EN0rI/ruvkryBjaxvJveAoODaeochVRehENqz1qSMWw="
 }