diff --git a/Dockerfile.test b/Dockerfile.test
index a8ccfeb..657d2de 100644
--- a/Dockerfile.test
+++ b/Dockerfile.test
@@ -37,13 +37,12 @@ WORKDIR /build/akku
 RUN bash install.sh
 ENV PATH=/root/.local/bin:${PATH}
 RUN akku update
-WORKDIR /workdir
-RUN snow-chibi install --impls=${SCHEME} --always-yes "(srfi 64)"
-RUN snow-chibi update
 WORKDIR /build/r7rs-srfi
-RUN make SCHEME=${SCHEME} SRFI=60 build install
-RUN make SCHEME=${SCHEME} SRFI=145 build install
-RUN make SCHEME=${SCHEME} SRFI=180 build install
+RUN make SCHEME=${SCHEME} SRFI=60 SNOW_FORT_ARGS=--always-yes build install
+RUN make SCHEME=${SCHEME} SRFI=39 SNOW_FORT_ARGS=--always-yes build install
+RUN make SCHEME=${SCHEME} SRFI=64 SNOW_FORT_ARGS=--always-yes build install
+RUN make SCHEME=${SCHEME} SRFI=145 SNOW_FORT_ARGS=--always-yes build install
+RUN make SCHEME=${SCHEME} SRFI=180 SNOW_FORT_ARGS=--always-yes build install
 WORKDIR /workdir
 COPY Makefile .
 COPY retropikzel retropikzel/
diff --git a/Makefile b/Makefile
index 1233bd1..dc36283 100644
--- a/Makefile
+++ b/Makefile
@@ -54,7 +54,6 @@ test-r6rs: ${TMPDIR}
 test-r6rs-docker: ${TMPDIR}
 	echo "Building docker image..."
 	docker build --build-arg IMAGE=${DOCKERIMG} --build-arg SCHEME=${SCHEME} --tag=${DOCKER_TAG} -f Dockerfile.test ${DOCKER_QUIET} . > /dev/null
-	docker stop $$(docker ps -a -q --filter ancestor=${DOCKER_TAG} --format="{{.ID}}") > /dev/null || true
 	docker run -t ${DOCKER_TAG} sh -c "make SCHEME=${SCHEME} SNOW_CHIBI_ARGS=--always-yes LIBRARY=${LIBRARY} test-r6rs"
 
 test-r7rs: ${TMPDIR}
@@ -66,7 +65,6 @@ test-r7rs: ${TMPDIR}
 test-r7rs-docker: ${TMPDIR}
 	echo "Building docker image..."
 	docker build --build-arg IMAGE=${DOCKERIMG} --build-arg SCHEME=${SCHEME} --tag=${DOCKER_TAG} -f Dockerfile.test ${DOCKER_QUIET} . > /dev/null
-	docker stop $$(docker ps -a -q --filter ancestor=${DOCKER_TAG} --format="{{.ID}}") > /dev/null || true
 	docker run -t ${DOCKER_TAG} sh -c "make SCHEME=${SCHEME} SNOW_CHIBI_ARGS=--always-yes LIBRARY=${LIBRARY} test-r7rs"
 
 clean: