diff --git a/test/cases/040_packages/005_extend/000_ext4/Dockerfile b/test/cases/040_packages/005_extend/000_ext4/Dockerfile
deleted file mode 100644
index 7d65b7bf1..000000000
--- a/test/cases/040_packages/005_extend/000_ext4/Dockerfile
+++ /dev/null
@@ -1,2 +0,0 @@
-FROM alpine:3.6
-RUN apk add --no-cache qemu-img sfdisk e2fsprogs util-linux
diff --git a/test/cases/040_packages/005_extend/000_ext4/extend.sh b/test/cases/040_packages/005_extend/000_ext4/extend.sh
deleted file mode 100755
index f7f9e5788..000000000
--- a/test/cases/040_packages/005_extend/000_ext4/extend.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/sh
-set -ex
-qemu-img resize -f qcow2 "$1" +256M
diff --git a/test/cases/040_packages/005_extend/000_ext4/test.sh b/test/cases/040_packages/005_extend/000_ext4/test.sh
index 91b8e86a2..725b5c84b 100644
--- a/test/cases/040_packages/005_extend/000_ext4/test.sh
+++ b/test/cases/040_packages/005_extend/000_ext4/test.sh
@@ -9,24 +9,22 @@ set -ex
 #. "${RT_LIB}"
 . "${RT_PROJECT_ROOT}/_lib/lib.sh"
 
-NAME=test-extend
+NAME=test-extend-ext4
 DISK=disk0.img
 clean_up() {
 	find . -depth -iname "${NAME}*" -not -iname "*.yml" -exec rm -rf {} \;
+	rm -rf "create*" || true
 	rm -rf ${DISK} || true
-	docker rmi ${NAME} || true
 }
 
 trap clean_up EXIT
 
 # Test code goes here
-rm -rf ${DISK} || true
-docker build -t ${NAME} .
 moby build --name create -output kernel+initrd test-create.yml
-linuxkit run -disk file=${DISK},size=256M create
-rm -rf "create*"
+linuxkit run -disk file=${DISK},format=raw,size=256M create
 [ -f ${DISK} ] || exit 1
-docker run -i --rm --privileged -v "$PWD:/tmp" -w /tmp ${NAME} ./extend.sh ${DISK}
+# osx takes issue with bs=1M
+dd if=/dev/zero bs=1048576 count=256 >> ${DISK}
 moby build -name ${NAME} -output kernel+initrd test.yml
 RESULT="$(linuxkit run -disk file=${DISK} ${NAME})"
 echo "${RESULT}"
diff --git a/test/cases/040_packages/005_extend/001_btrfs/Dockerfile b/test/cases/040_packages/005_extend/001_btrfs/Dockerfile
deleted file mode 100644
index 7d65b7bf1..000000000
--- a/test/cases/040_packages/005_extend/001_btrfs/Dockerfile
+++ /dev/null
@@ -1,2 +0,0 @@
-FROM alpine:3.6
-RUN apk add --no-cache qemu-img sfdisk e2fsprogs util-linux
diff --git a/test/cases/040_packages/005_extend/001_btrfs/extend.sh b/test/cases/040_packages/005_extend/001_btrfs/extend.sh
deleted file mode 100755
index f7f9e5788..000000000
--- a/test/cases/040_packages/005_extend/001_btrfs/extend.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/sh
-set -ex
-qemu-img resize -f qcow2 "$1" +256M
diff --git a/test/cases/040_packages/005_extend/001_btrfs/test.sh b/test/cases/040_packages/005_extend/001_btrfs/test.sh
index 9649bc8f6..6bd095676 100644
--- a/test/cases/040_packages/005_extend/001_btrfs/test.sh
+++ b/test/cases/040_packages/005_extend/001_btrfs/test.sh
@@ -9,24 +9,22 @@ set -ex
 #. "${RT_LIB}"
 . "${RT_PROJECT_ROOT}/_lib/lib.sh"
 
-NAME=test-extend
+NAME=test-extend-btrfs
 DISK=disk0.img
 clean_up() {
 	find . -depth -iname "${NAME}*" -not -iname "*.yml" -exec rm -rf {} \;
+	rm -rf "create*" || true
 	rm -rf ${DISK} || true
-	docker rmi ${NAME} || true
 }
 
 trap clean_up EXIT
 
 # Test code goes here
-rm -rf disk0.img || true
-docker build -t ${NAME} .
 moby build --name create -output kernel+initrd test-create.yml
-linuxkit run -disk file=${DISK},size=256M create
-rm -rf "create*"
+linuxkit run -disk file=${DISK},format=raw,size=256M create
 [ -f ${DISK} ] || exit 1
-docker run -i --rm --privileged -v "$PWD:/tmp" -w /tmp ${NAME} ./extend.sh ${DISK}
+# osx takes issue with bs=1M
+dd if=/dev/zero bs=1048576 count=256 >> ${DISK}
 moby build -name ${NAME} -output kernel+initrd test.yml
 RESULT="$(linuxkit run -disk file=${DISK} ${NAME})"
 echo "${RESULT}"
diff --git a/test/cases/040_packages/005_extend/002_xfs/Dockerfile b/test/cases/040_packages/005_extend/002_xfs/Dockerfile
deleted file mode 100644
index 7d65b7bf1..000000000
--- a/test/cases/040_packages/005_extend/002_xfs/Dockerfile
+++ /dev/null
@@ -1,2 +0,0 @@
-FROM alpine:3.6
-RUN apk add --no-cache qemu-img sfdisk e2fsprogs util-linux
diff --git a/test/cases/040_packages/005_extend/002_xfs/check.sh b/test/cases/040_packages/005_extend/002_xfs/check.sh
index 4523db10d..943fabc04 100755
--- a/test/cases/040_packages/005_extend/002_xfs/check.sh
+++ b/test/cases/040_packages/005_extend/002_xfs/check.sh
@@ -9,5 +9,5 @@ function failed {
 
 [ -f /var/lib/docker/bar ] || failed
 touch /var/lib/docker/foo || failed
-df -h | grep -q "507.7M" || failed
+df -h | grep -q "504.8M" || failed
 printf "extend test suite PASSED\n" >&1
diff --git a/test/cases/040_packages/005_extend/002_xfs/extend.sh b/test/cases/040_packages/005_extend/002_xfs/extend.sh
deleted file mode 100755
index f7f9e5788..000000000
--- a/test/cases/040_packages/005_extend/002_xfs/extend.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/sh
-set -ex
-qemu-img resize -f qcow2 "$1" +256M
diff --git a/test/cases/040_packages/005_extend/002_xfs/test.sh b/test/cases/040_packages/005_extend/002_xfs/test.sh
index cc05a834f..7c264b410 100644
--- a/test/cases/040_packages/005_extend/002_xfs/test.sh
+++ b/test/cases/040_packages/005_extend/002_xfs/test.sh
@@ -9,24 +9,22 @@ set -ex
 #. "${RT_LIB}"
 . "${RT_PROJECT_ROOT}/_lib/lib.sh"
 
-NAME=test-extend
+NAME=test-extend-xfs
 DISK=disk0.img
 clean_up() {
 	find . -depth -iname "${NAME}*" -not -iname "*.yml" -exec rm -rf {} \;
+	rm -rf "create*" || true
 	rm -rf ${DISK} || true
-	docker rmi ${NAME} || true
 }
 
 trap clean_up EXIT
 
 # Test code goes here
-rm -rf disk0.img || true
-docker build -t ${NAME} .
 moby build --name create -output kernel+initrd test-create.yml
-linuxkit run -disk file=${DISK},size=256M create
-rm -rf "create*"
+linuxkit run -disk file=${DISK},format=raw,size=256M create
 [ -f ${DISK} ] || exit 1
-docker run -i --rm --privileged -v "$PWD:/tmp" -w /tmp ${NAME} ./extend.sh ${DISK}
+# osx takes issue with bs=1M
+dd if=/dev/zero bs=1048576 count=256 >> ${DISK}
 moby build -name ${NAME} -output kernel+initrd test.yml
 RESULT="$(linuxkit run -disk file=${DISK} ${NAME})"
 echo "${RESULT}"