diff --git a/justfile b/justfile
index 20a34a0..ad3f962 100644
--- a/justfile
+++ b/justfile
@@ -7,11 +7,15 @@ default:
 build:
     docker build . -t research-template
 
-test-smoke:
+check-image-exists:
+    # Extra brackets are for Just escaping.
+    docker image inspect --format='{{{{.Id}}}}' research-template
+
+test-smoke: check-image-exists
     docker run --rm research-template ls /opt/venv/bin/python3.10
 
-test-packages:
+test-packages: check-image-exists
     tests/packages.sh
 
-test-rstudio:
+test-rstudio: check-image-exists
     docker run -i --entrypoint /bin/bash research-template < ./tests/r_studio.sh