diff --git a/tests/acceptance/docker/Makefile b/tests/acceptance/docker/Makefile
index 5d4461c25..f11c532a5 100644
--- a/tests/acceptance/docker/Makefile
+++ b/tests/acceptance/docker/Makefile
@@ -48,6 +48,13 @@ else
 	SEARCH_EXTRACTOR_TYPE := basic
 endif
 
+# default to decomposedfs
+STORAGE_DRIVER ?= decomposed
+ifeq ($(STORAGE_DRIVER),posix)
+	# posix requires a additional driver config
+	COMPOSE_FILE := $(COMPOSE_FILE):src/posix.yml
+endif
+
 # static
 DIVIDE_INTO_NUM_PARTS := 10
 PARTS = 1 2 3 4 5 6 7 8 9 10
@@ -296,7 +303,7 @@ start-server: $(OC_WRAPPER) ## build and start server
 	OC_IMAGE_TAG=dev \
 	WITH_WRAPPER=$(WITH_WRAPPER) \
 	TEST_SOURCE=opencloud \
-	STORAGE_DRIVER=decomposed \
+	STORAGE_DRIVER=$(STORAGE_DRIVER) \
 	OC_ASYNC_UPLOADS=true \
 	SEARCH_EXTRACTOR_TYPE=tika \
 	OC_ADD_RUN_SERVICES=notifications \
diff --git a/tests/acceptance/docker/src/posix.yml b/tests/acceptance/docker/src/posix.yml
new file mode 100644
index 000000000..893352cd5
--- /dev/null
+++ b/tests/acceptance/docker/src/posix.yml
@@ -0,0 +1,8 @@
+---
+services:
+  opencloud-server:
+    environment:
+      # activate posix storage driver for users
+      STORAGE_USERS_DRIVER: posix
+      # posix requires a shared cache store
+      STORAGE_USERS_ID_CACHE_STORE: "nats-js-kv"