diff --git a/dockerfiles/Dockerfile.test b/dockerfiles/Dockerfile.test
index cce20ce..4938691 100644
--- a/dockerfiles/Dockerfile.test
+++ b/dockerfiles/Dockerfile.test
@@ -1,3 +1,4 @@
+ARG COMPILE_R7RS=chibi
 FROM schemers/${COMPILE_R7RS}
 RUN apt-get update && apt-get install -y \
     build-essential \