diff --git a/Dockerfile.jenkins b/Dockerfile.jenkins
index 2fd7216..b7720a9 100644
--- a/Dockerfile.jenkins
+++ b/Dockerfile.jenkins
@@ -1,4 +1,4 @@
 FROM schemers/chibi:head
 RUN apt-get update && apt-get install -y \
-    gcc ca-certificates libffi-dev docker.io
+    gcc ca-certificates libffi-dev docker.io make
 RUN snow-chibi install --impls=chibi retropikzel.test-r7rs
diff --git a/Makefile b/Makefile
index 9001c02..7446452 100644
--- a/Makefile
+++ b/Makefile
@@ -56,6 +56,7 @@ testfiles: ${PKG}
 
 test: testfiles
 	cd ${tmpdir} && \
+		COMPILE_R7RS_DEBUG=1 \
 		COMPILE_R7RS=${SCHEME} \
 		CSC_OPTIONS="${CSC_OPTIONS}" \
 		compile-r7rs ${LIB_PATHS} -o test-program test.${SFX}