diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 7dfcb48..d36a180 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,4 +1,4 @@
-image: nixos/nix
+image: nixos/nix:2.17.1
 
 variables:
   NIXOS_VERSION: "unstable"