diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 55a948019..43c6b825e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -6,7 +6,7 @@ workflow:
 
 default:
   image:
-    name: registry.gitlab.com/fradrive/fradrive/nix-unstable
+    name: registry.gitlab.com/fradrive/fradrive/nix-unstable:kkq79z2lyip9wasq9sfd8mgqgifj9prs
 
 variables:
   NIX_PATH: "nixpkgs=http://nixos.org/channels/nixos-21.05/nixexprs.tar.xz"