diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3449776e00947baececdfc26e07e165aa37359b6..85d380401ae46f6a9c02c7891a652cb4483cbe57 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -32,6 +32,9 @@ morph-builds:
     # This is far from ideal but maybe it's a tolerable hack for now.
     - "nixos"
     - "docker"
+
+  image: "nixos/nix:latest"
+
   stage: "test"
   variables:
     # CACHIX_AUTH_TOKEN, which lets us push to cachix, is supplied by GitLab