diff --git a/.drone.yml b/.drone.yml
index 310d093..4a4f3d4 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -17,8 +17,8 @@ steps:
   - name: compute cache key
     image: docker.io/library/elixir:1.18.3-otp-27
     commands:
-      - echo "$DRONE_REPO_OWNER/$DRONE_REPO_NAME" >> .cache_key
-      - echo $(sha256sum mix.lock | cut -d ' ' -f 1) >> .cache_key
+      - mix_lock_hash=$(sha256sum mix.lock | cut -d ' ' -f 1)
+      - echo "$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$mix_lock_hash" >> .cache_key
       # Print cache key for debugging
       - cat .cache_key