diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 754e3bc..0c1d997 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -17,8 +17,8 @@ jobs:
         channel:
           - nixos-unstable
           - nixos-20.09
-          - nixos-20.03
           - nixos-21.05
+          - nixos-21.11
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b5907ff..8ef45cb 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -3,13 +3,13 @@ stages:
 
 build:
   stage: build
-  image: nixpkgs/nix:nixos-20.03
+  image: nixpkgs/nix:nixos-21.05
   script: nix-shell --run ./ci.sh
   parallel:
     matrix:
       - NIXPKGS_CHANNEL: nixos-unstable
         IMAGE_TAG: latest
       - NIXPKGS_CHANNEL:
-          - nixos-20.03
           - nixos-20.09
           - nixos-21.05
+          - nixos-21.11
diff --git a/README.md b/README.md
index 1709470..7726a55 100644
--- a/README.md
+++ b/README.md
@@ -39,10 +39,10 @@ nixpkgs channel describes.
 
 | Channel        | Image Tag   | Description                                       |
 | ---            | ---         | ---                                               |
-| nixos-unstable | latest      | latest and greatest, major versions might change   |
+| nixos-unstable | latest      | latest and greatest, major versions might change  |
+| nixos-21.11    | nixos-21.11 | only minor versions that include security updates |
+| nixos-21.05    | nixos-21.05 | only minor versions that include security updates |
 | nixos-20.09    | nixos-20.09 | only minor versions that include security updates |
-| nixos-20.03    | nixos-20.03 | only minor versions that include security updates |
-| nixos-21.05    | nixos-21.04 | only minor versions that include security updates |
 
 ## List of images