diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 27c7842..af017b0 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,29 +1,17 @@
-image: nixos/nix:latest
+image: nixpkgs/nix:nixos-20.03
 
 stages:
   - build
 
 nixos-unstable:
   stage: build
-  script: nix-shell --run ./.gitlab-ci.sh
+  script: NIX_PATH=channel:$NIXPKGS_CHANNEL nix-shell --run ./.gitlab-ci.sh
   variables:
     NIXPKGS_CHANNEL: nixos-unstable
     IMAGE_TAG: latest
 
 nixos-20.03:
   stage: build
-  script: nix-shell --run ./.gitlab-ci.sh
+  script: NIX_PATH=channel:$NIXPKGS_CHANNEL nix-shell --run ./.gitlab-ci.sh
   variables:
     NIXPKGS_CHANNEL: nixos-20.03
-
-nixos-19.09:
-  stage: build
-  script: nix-shell --run ./.gitlab-ci.sh
-  variables:
-    NIXPKGS_CHANNEL: nixos-19.09
-
-nixos-19.03:
-  stage: build
-  script: nix-shell --run ./.gitlab-ci.sh
-  variables:
-    NIXPKGS_CHANNEL: nixos-19.03
diff --git a/.travis.yml b/.travis.yml
index 1ed8ff4..1f8bb86 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: nix
 
-nix: 2.2.1
+nix: 2.3.6
 
 matrix:
   include:
@@ -8,10 +8,6 @@ matrix:
     env: NIXPKGS_CHANNEL=nixos-unstable IMAGE_TAG=latest
   - name: nixos-20.03
     env: NIXPKGS_CHANNEL=nixos-20.03
-  - name: nixos-19.09
-    env: NIXPKGS_CHANNEL=nixos-19.09
-  - name: nixos-19.03
-    env: NIXPKGS_CHANNEL=nixos-19.03
 
 script:
-  - nix-shell --run ./.travis.sh
+  - NIX_PATH=channel:$NIXPKGS_CHANNEL nix-shell --run ./.travis.sh
diff --git a/README.md b/README.md
index bf4aa72..b36a657 100644
--- a/README.md
+++ b/README.md
@@ -58,9 +58,7 @@ nixpkgs channel describes.
 | Channel        | Image Tag   | Description                                       |
 | ---            | ---         | ---                                               |
 | nixos-unstable | latest      | latest and greated, major versions might change   |
-| nixos-20.03    | nixos-20.03 | next release, still baking                        |
-| nixos-19.09    | nixos-19.09 | only minor versions that include security updates |
-| nixos-19.03    | nixos-19.03 | only minor versions that include security updates |
+| nixos-20.03    | nixos-20.03 | only minor versions that include security updates |
 
 ## Docker Hub
 
@@ -70,24 +68,24 @@ All images are automatically built and pushed to Docker Hub.
 
 `> ./dockerhub-image-matrix`
 <!-- BEGIN mdsh -->
-| Image / Tag | latest | nixos-20.03 | nixos-19.09 | nixos-19.03 |
-| ---         | ---    | ---         | ---         | ---         |
-| [nixpkgs/bash](https://hub.docker.com/r/nixpkgs/bash) | [![](https://images.microbadger.com/badges/image/nixpkgs/bash.svg)](https://microbadger.com/images/nixpkgs/bash) | [![](https://images.microbadger.com/badges/image/nixpkgs/bash:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/bash:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/bash:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/bash:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/bash:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/bash:nixos-19.03) |
-| [nixpkgs/busybox](https://hub.docker.com/r/nixpkgs/busybox) | [![](https://images.microbadger.com/badges/image/nixpkgs/busybox.svg)](https://microbadger.com/images/nixpkgs/busybox) | [![](https://images.microbadger.com/badges/image/nixpkgs/busybox:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/busybox:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/busybox:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/busybox:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/busybox:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/busybox:nixos-19.03) |
-| [nixpkgs/cachix](https://hub.docker.com/r/nixpkgs/cachix) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix.svg)](https://microbadger.com/images/nixpkgs/cachix) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/cachix:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/cachix:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/cachix:nixos-19.03) |
-| [nixpkgs/cachix-flakes](https://hub.docker.com/r/nixpkgs/cachix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix-flakes.svg)](https://microbadger.com/images/nixpkgs/cachix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix-flakes:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/cachix-flakes:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix-flakes:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/cachix-flakes:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix-flakes:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/cachix-flakes:nixos-19.03) |
-| [nixpkgs/caddy](https://hub.docker.com/r/nixpkgs/caddy) | [![](https://images.microbadger.com/badges/image/nixpkgs/caddy.svg)](https://microbadger.com/images/nixpkgs/caddy) | [![](https://images.microbadger.com/badges/image/nixpkgs/caddy:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/caddy:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/caddy:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/caddy:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/caddy:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/caddy:nixos-19.03) |
-| [nixpkgs/couchpotato](https://hub.docker.com/r/nixpkgs/couchpotato) | [![](https://images.microbadger.com/badges/image/nixpkgs/couchpotato.svg)](https://microbadger.com/images/nixpkgs/couchpotato) | [![](https://images.microbadger.com/badges/image/nixpkgs/couchpotato:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/couchpotato:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/couchpotato:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/couchpotato:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/couchpotato:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/couchpotato:nixos-19.03) |
-| [nixpkgs/curl](https://hub.docker.com/r/nixpkgs/curl) | [![](https://images.microbadger.com/badges/image/nixpkgs/curl.svg)](https://microbadger.com/images/nixpkgs/curl) | [![](https://images.microbadger.com/badges/image/nixpkgs/curl:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/curl:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/curl:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/curl:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/curl:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/curl:nixos-19.03) |
-| [nixpkgs/devcontainer](https://hub.docker.com/r/nixpkgs/devcontainer) | [![](https://images.microbadger.com/badges/image/nixpkgs/devcontainer.svg)](https://microbadger.com/images/nixpkgs/devcontainer) | [![](https://images.microbadger.com/badges/image/nixpkgs/devcontainer:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/devcontainer:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/devcontainer:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/devcontainer:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/devcontainer:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/devcontainer:nixos-19.03) |
-| [nixpkgs/docker-compose](https://hub.docker.com/r/nixpkgs/docker-compose) | [![](https://images.microbadger.com/badges/image/nixpkgs/docker-compose.svg)](https://microbadger.com/images/nixpkgs/docker-compose) | [![](https://images.microbadger.com/badges/image/nixpkgs/docker-compose:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/docker-compose:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/docker-compose:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/docker-compose:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/docker-compose:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/docker-compose:nixos-19.03) |
-| [nixpkgs/hugo](https://hub.docker.com/r/nixpkgs/hugo) | [![](https://images.microbadger.com/badges/image/nixpkgs/hugo.svg)](https://microbadger.com/images/nixpkgs/hugo) | [![](https://images.microbadger.com/badges/image/nixpkgs/hugo:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/hugo:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/hugo:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/hugo:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/hugo:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/hugo:nixos-19.03) |
-| [nixpkgs/kubectl](https://hub.docker.com/r/nixpkgs/kubectl) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubectl.svg)](https://microbadger.com/images/nixpkgs/kubectl) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubectl:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/kubectl:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubectl:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/kubectl:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubectl:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/kubectl:nixos-19.03) |
-| [nixpkgs/kubernetes-helm](https://hub.docker.com/r/nixpkgs/kubernetes-helm) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubernetes-helm.svg)](https://microbadger.com/images/nixpkgs/kubernetes-helm) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubernetes-helm:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/kubernetes-helm:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubernetes-helm:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/kubernetes-helm:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubernetes-helm:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/kubernetes-helm:nixos-19.03) |
-| [nixpkgs/nginx](https://hub.docker.com/r/nixpkgs/nginx) | [![](https://images.microbadger.com/badges/image/nixpkgs/nginx.svg)](https://microbadger.com/images/nixpkgs/nginx) | [![](https://images.microbadger.com/badges/image/nixpkgs/nginx:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nginx:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/nginx:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/nginx:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/nginx:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/nginx:nixos-19.03) |
-| [nixpkgs/nix](https://hub.docker.com/r/nixpkgs/nix) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix.svg)](https://microbadger.com/images/nixpkgs/nix) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nix:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/nix:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/nix:nixos-19.03) |
-| [nixpkgs/nix-flakes](https://hub.docker.com/r/nixpkgs/nix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-flakes.svg)](https://microbadger.com/images/nixpkgs/nix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-flakes:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nix-flakes:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-flakes:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/nix-flakes:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-flakes:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/nix-flakes:nixos-19.03) |
-| [nixpkgs/nix-unstable](https://hub.docker.com/r/nixpkgs/nix-unstable) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-unstable.svg)](https://microbadger.com/images/nixpkgs/nix-unstable) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-unstable:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nix-unstable:nixos-20.03) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-unstable:nixos-19.09.svg)](https://microbadger.com/images/nixpkgs/nix-unstable:nixos-19.09) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-unstable:nixos-19.03.svg)](https://microbadger.com/images/nixpkgs/nix-unstable:nixos-19.03) |
+| Image / Tag | latest | nixos-20.03 |
+| ---         | ---    | ---         |
+| [nixpkgs/bash](https://hub.docker.com/r/nixpkgs/bash) | [![](https://images.microbadger.com/badges/image/nixpkgs/bash.svg)](https://microbadger.com/images/nixpkgs/bash) | [![](https://images.microbadger.com/badges/image/nixpkgs/bash:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/bash:nixos-20.03) |
+| [nixpkgs/busybox](https://hub.docker.com/r/nixpkgs/busybox) | [![](https://images.microbadger.com/badges/image/nixpkgs/busybox.svg)](https://microbadger.com/images/nixpkgs/busybox) | [![](https://images.microbadger.com/badges/image/nixpkgs/busybox:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/busybox:nixos-20.03) |
+| [nixpkgs/cachix](https://hub.docker.com/r/nixpkgs/cachix) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix.svg)](https://microbadger.com/images/nixpkgs/cachix) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/cachix:nixos-20.03) |
+| [nixpkgs/cachix-flakes](https://hub.docker.com/r/nixpkgs/cachix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix-flakes.svg)](https://microbadger.com/images/nixpkgs/cachix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/cachix-flakes:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/cachix-flakes:nixos-20.03) |
+| [nixpkgs/caddy](https://hub.docker.com/r/nixpkgs/caddy) | [![](https://images.microbadger.com/badges/image/nixpkgs/caddy.svg)](https://microbadger.com/images/nixpkgs/caddy) | [![](https://images.microbadger.com/badges/image/nixpkgs/caddy:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/caddy:nixos-20.03) |
+| [nixpkgs/couchpotato](https://hub.docker.com/r/nixpkgs/couchpotato) | [![](https://images.microbadger.com/badges/image/nixpkgs/couchpotato.svg)](https://microbadger.com/images/nixpkgs/couchpotato) | [![](https://images.microbadger.com/badges/image/nixpkgs/couchpotato:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/couchpotato:nixos-20.03) |
+| [nixpkgs/curl](https://hub.docker.com/r/nixpkgs/curl) | [![](https://images.microbadger.com/badges/image/nixpkgs/curl.svg)](https://microbadger.com/images/nixpkgs/curl) | [![](https://images.microbadger.com/badges/image/nixpkgs/curl:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/curl:nixos-20.03) |
+| [nixpkgs/devcontainer](https://hub.docker.com/r/nixpkgs/devcontainer) | [![](https://images.microbadger.com/badges/image/nixpkgs/devcontainer.svg)](https://microbadger.com/images/nixpkgs/devcontainer) | [![](https://images.microbadger.com/badges/image/nixpkgs/devcontainer:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/devcontainer:nixos-20.03) |
+| [nixpkgs/docker-compose](https://hub.docker.com/r/nixpkgs/docker-compose) | [![](https://images.microbadger.com/badges/image/nixpkgs/docker-compose.svg)](https://microbadger.com/images/nixpkgs/docker-compose) | [![](https://images.microbadger.com/badges/image/nixpkgs/docker-compose:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/docker-compose:nixos-20.03) |
+| [nixpkgs/hugo](https://hub.docker.com/r/nixpkgs/hugo) | [![](https://images.microbadger.com/badges/image/nixpkgs/hugo.svg)](https://microbadger.com/images/nixpkgs/hugo) | [![](https://images.microbadger.com/badges/image/nixpkgs/hugo:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/hugo:nixos-20.03) |
+| [nixpkgs/kubectl](https://hub.docker.com/r/nixpkgs/kubectl) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubectl.svg)](https://microbadger.com/images/nixpkgs/kubectl) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubectl:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/kubectl:nixos-20.03) |
+| [nixpkgs/kubernetes-helm](https://hub.docker.com/r/nixpkgs/kubernetes-helm) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubernetes-helm.svg)](https://microbadger.com/images/nixpkgs/kubernetes-helm) | [![](https://images.microbadger.com/badges/image/nixpkgs/kubernetes-helm:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/kubernetes-helm:nixos-20.03) |
+| [nixpkgs/nginx](https://hub.docker.com/r/nixpkgs/nginx) | [![](https://images.microbadger.com/badges/image/nixpkgs/nginx.svg)](https://microbadger.com/images/nixpkgs/nginx) | [![](https://images.microbadger.com/badges/image/nixpkgs/nginx:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nginx:nixos-20.03) |
+| [nixpkgs/nix](https://hub.docker.com/r/nixpkgs/nix) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix.svg)](https://microbadger.com/images/nixpkgs/nix) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nix:nixos-20.03) |
+| [nixpkgs/nix-flakes](https://hub.docker.com/r/nixpkgs/nix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-flakes.svg)](https://microbadger.com/images/nixpkgs/nix-flakes) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-flakes:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nix-flakes:nixos-20.03) |
+| [nixpkgs/nix-unstable](https://hub.docker.com/r/nixpkgs/nix-unstable) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-unstable.svg)](https://microbadger.com/images/nixpkgs/nix-unstable) | [![](https://images.microbadger.com/badges/image/nixpkgs/nix-unstable:nixos-20.03.svg)](https://microbadger.com/images/nixpkgs/nix-unstable:nixos-20.03) |
 <!-- END mdsh -->
 ## Adding new images
 
diff --git a/dockerhub-image-matrix b/dockerhub-image-matrix
index 7a79c67..3439f38 100755
--- a/dockerhub-image-matrix
+++ b/dockerhub-image-matrix
@@ -23,10 +23,10 @@ microbadge() {
 
 releases_json=$(nix-instantiate --strict --eval --json)
 
-echo "| Image / Tag | latest | nixos-20.03 | nixos-19.09 | nixos-19.03 |"
-echo "| ---         | ---    | ---         | ---         | ---         |"
+echo "| Image / Tag | latest | nixos-20.03 |"
+echo "| ---         | ---    | ---         |"
 
 for attr in $(echo "$releases_json" | jq -r "keys[]") ; do
   name=nixpkgs/$attr
-  echo "| [$name](https://hub.docker.com/r/$name) | $(microbadge "$name") | $(microbadge "$name" "nixos-20.03") | $(microbadge "$name" "nixos-19.09") | $(microbadge "$name" "nixos-19.03") |"
+  echo "| [$name](https://hub.docker.com/r/$name) | $(microbadge "$name") | $(microbadge "$name" "nixos-20.03") |"
 done
diff --git a/images/devcontainer/default.nix b/images/devcontainer/default.nix
index ef5163c..337f24c 100644
--- a/images/devcontainer/default.nix
+++ b/images/devcontainer/default.nix
@@ -112,11 +112,13 @@ let
         "PAGER=less"
         "PATH=/nix/var/nix/profiles/default/bin"
         "SSL_CERT_FILE=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"
-      ]
-      ++ lib.optional
-        (channel != "")
-        "NIX_PATH=nixpkgs=channel:${channel}"
-      ;
+        (
+          if channel != "" then
+            "NIX_PATH=nixpkgs=channel:${channel}"
+          else
+            "NIX_PATH=nixpkgs=${../nix/fake_nixpkgs}"
+        )
+      ];
       Labels = {
         # https://github.com/microscaling/microscaling/blob/55a2d7b91ce7513e07f8b1fd91bbed8df59aed5a/Dockerfile#L22-L33
         "org.label-schema.vcs-ref" = "master";
diff --git a/shell.nix b/shell.nix
index 0b53ad4..ff83b27 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,5 +1,5 @@
 let
-  nixpkgs = builtins.fetchTarball "channel:nixos-19.09";
+  nixpkgs = builtins.fetchTarball "channel:nixos-20.03";
   pkgs = import nixpkgs { config = {}; overlays = []; };
 in
 with pkgs;