diff --git a/.github/workflows/update-flake-lock.yml b/.github/workflows/update-flake-lock.yml
index 7b45f15..d35fb5d 100644
--- a/.github/workflows/update-flake-lock.yml
+++ b/.github/workflows/update-flake-lock.yml
@@ -20,8 +20,6 @@ jobs:
         branch:
           - master
           - nixos-24.05
-          - nixos-23.11
-          - nixos-23.05
     permissions:
       contents: write # to create branch
       pull-requests: write # to create PR to backport