diff --git a/.drone.yml b/.drone.yml
index 1f38d79..7b5027b 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -26,7 +26,7 @@ steps:
     commands:
       - cd ./src/rust/namegen-lambda
       - apt-get update
-      - apt-get install -y python3-pip
+      - apt-get install -y python3-pip tree
       - python3 -m pip install --upgrade pip
       - python3 -m pip install cargo-lambda
       - cargo lambda build --release