diff --git a/.github/workflows/periodic-merge-24h.yml b/.github/workflows/periodic-merge-24h.yml
index 270283bff478..bd7aadfbade1 100644
--- a/.github/workflows/periodic-merge-24h.yml
+++ b/.github/workflows/periodic-merge-24h.yml
@@ -35,10 +35,6 @@ jobs:
         pairs:
           - from: master
             into: haskell-updates
-          - from: release-23.05
-            into: staging-next-23.05
-          - from: staging-next-23.05
-            into: staging-23.05
           - from: release-23.11
             into: staging-next-23.11
           - from: staging-next-23.11
diff --git a/lib/trivial.nix b/lib/trivial.nix
index b2796096e8bc..f27cfb04f074 100644
--- a/lib/trivial.nix
+++ b/lib/trivial.nix
@@ -189,7 +189,7 @@ in {
      they take effect as soon as the oldest release reaches end of life. */
   oldestSupportedRelease =
     # Update on master only. Do not backport.
-    2305;
+    2311;
 
   /* Whether a feature is supported in all supported releases (at the time of
      release branch-off, if applicable). See `oldestSupportedRelease`. */