diff --git a/docker-compose.yml b/docker-compose.yml
index 49ffa6b2..fbc3fc49 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -18,6 +18,7 @@ services:
       - WORKSPACE=/home/docker/.autotesting
       - SUPERVISOR_URL=127.0.0.1:9001
       - AUTOTESTER_CONFIG=/app/.dockerfiles/docker-config.yml
+      - STACK_ROOT=/home/docker/.autotesting/.stack
     depends_on:
       - postgres
       - redis