diff --git a/.github/ISSUE_TEMPLATE/01_bug_report.yml b/.github/ISSUE_TEMPLATE/01_bug_report.yml
index d2ed16e343e9..07263b4ca2a4 100644
--- a/.github/ISSUE_TEMPLATE/01_bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/01_bug_report.yml
@@ -37,7 +37,6 @@ body:
         - "Please select a version."
         - "- Unstable (26.05)"
         - "- Stable (25.11)"
-        - "- Old Stable (25.05)"
       default: 0
     validations:
       required: true
diff --git a/.github/ISSUE_TEMPLATE/02_bug_report_darwin.yml b/.github/ISSUE_TEMPLATE/02_bug_report_darwin.yml
index 7acda0e781c5..dd26d3f658d6 100644
--- a/.github/ISSUE_TEMPLATE/02_bug_report_darwin.yml
+++ b/.github/ISSUE_TEMPLATE/02_bug_report_darwin.yml
@@ -37,7 +37,6 @@ body:
         - "Please select a version."
         - "- Unstable (26.05)"
         - "- Stable (25.11)"
-        - "- Old Stable (25.05)"
       default: 0
     validations:
       required: true
diff --git a/.github/ISSUE_TEMPLATE/03_bug_report_nixos.yml b/.github/ISSUE_TEMPLATE/03_bug_report_nixos.yml
index 532d7851e989..85daf0cc75cd 100644
--- a/.github/ISSUE_TEMPLATE/03_bug_report_nixos.yml
+++ b/.github/ISSUE_TEMPLATE/03_bug_report_nixos.yml
@@ -37,7 +37,6 @@ body:
         - "Please select a version."
         - "- Unstable (26.05)"
         - "- Stable (25.11)"
-        - "- Old Stable (25.05)"
       default: 0
     validations:
       required: true
diff --git a/.github/ISSUE_TEMPLATE/04_build_failure.yml b/.github/ISSUE_TEMPLATE/04_build_failure.yml
index 3d5354adca71..d986cd2fc1fa 100644
--- a/.github/ISSUE_TEMPLATE/04_build_failure.yml
+++ b/.github/ISSUE_TEMPLATE/04_build_failure.yml
@@ -39,7 +39,6 @@ body:
         - "Please select a version."
         - "- Unstable (26.05)"
         - "- Stable (25.11)"
-        - "- Old Stable (25.05)"
       default: 0
     validations:
       required: true
diff --git a/.github/ISSUE_TEMPLATE/05_update_request.yml b/.github/ISSUE_TEMPLATE/05_update_request.yml
index a575550eaee5..324d35450048 100644
--- a/.github/ISSUE_TEMPLATE/05_update_request.yml
+++ b/.github/ISSUE_TEMPLATE/05_update_request.yml
@@ -39,7 +39,6 @@ body:
         - "Please select a version."
         - "- Unstable (26.05)"
         - "- Stable (25.11)"
-        - "- Old Stable (25.05)"
       default: 0
     validations:
       required: true
diff --git a/.github/ISSUE_TEMPLATE/06_module_request.yml b/.github/ISSUE_TEMPLATE/06_module_request.yml
index fbe5a2a62a44..d2451720ccae 100644
--- a/.github/ISSUE_TEMPLATE/06_module_request.yml
+++ b/.github/ISSUE_TEMPLATE/06_module_request.yml
@@ -37,7 +37,6 @@ body:
         - "Please select a version."
         - "- Unstable (26.05)"
         - "- Stable (25.11)"
-        - "- Old Stable (25.05)"
       default: 0
     validations:
       required: true
diff --git a/.github/labeler-no-sync.yml b/.github/labeler-no-sync.yml
index b0bee8d48a72..1cb675a2a57b 100644
--- a/.github/labeler-no-sync.yml
+++ b/.github/labeler-no-sync.yml
@@ -22,17 +22,6 @@
               - doc/**/*
               - nixos/doc/**/*
 
-"backport release-25.05":
-  - all:
-      - changed-files:
-          - any-glob-to-any-file:
-              - .github/actions/*
-              - .github/workflows/*
-              - .github/labeler*.yml
-              - ci/**/*.*
-              - maintainers/github-teams.json
-      - base-branch: ['master']
-
 "backport release-25.11":
   - all:
       - changed-files:
diff --git a/.github/workflows/periodic-merge-24h.yml b/.github/workflows/periodic-merge-24h.yml
index 96d97f6df803..c80f3212ed21 100644
--- a/.github/workflows/periodic-merge-24h.yml
+++ b/.github/workflows/periodic-merge-24h.yml
@@ -31,10 +31,6 @@ jobs:
       max-parallel: 1
       matrix:
         pairs:
-          - from: release-25.05
-            into: staging-next-25.05
-          - from: staging-next-25.05
-            into: staging-25.05
           - from: release-25.11
             into: staging-next-25.11
           - from: staging-next-25.11
diff --git a/README.md b/README.md
index 531af2643e5d..1a4b04896144 100644
--- a/README.md
+++ b/README.md
@@ -47,9 +47,9 @@ Here are some of the main ones:
 Nixpkgs and NixOS are built and tested by our continuous integration system, [Hydra](https://hydra.nixos.org/).
 
 * [Continuous package builds for unstable/master](https://hydra.nixos.org/jobset/nixos/trunk-combined)
-* [Continuous package builds for the NixOS 25.05 release](https://hydra.nixos.org/jobset/nixos/release-25.05)
+* [Continuous package builds for the NixOS 25.11 release](https://hydra.nixos.org/jobset/nixos/release-25.11)
 * [Tests for unstable/master](https://hydra.nixos.org/job/nixos/trunk-combined/tested#tabs-constituents)
-* [Tests for the NixOS 25.05 release](https://hydra.nixos.org/job/nixos/release-25.05/tested#tabs-constituents)
+* [Tests for the NixOS 25.11 release](https://hydra.nixos.org/job/nixos/release-25.11/tested#tabs-constituents)
 
 Artifacts successfully built with Hydra are published to cache at https://cache.nixos.org/.
 When successful build and test criteria are met, the Nixpkgs expressions are distributed via [Nix channels](https://nix.dev/manual/nix/stable/command-ref/nix-channel.html).