diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 8e93296fab..49dfc34350 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -50,7 +50,7 @@ cd test-project
 set -a && . ../.env && set +a
 
 # run the test in an image built on top of the factory.
-docker compose run --rm test-factory-all-included
+docker compose run --build --rm test-factory-all-included
 ```
 
 ### Publishing images