diff --git a/ucloud/config.py b/ucloud/config.py
index a2f523f..a5b8f00 100644
--- a/ucloud/config.py
+++ b/ucloud/config.py
@@ -33,8 +33,8 @@ running_vms = []
 
 __storage_backend = env_vars.get("STORAGE_BACKEND", "filesystem")
 if __storage_backend == "filesystem":
-    image_storage_handler = FileSystemBasedImageStorageHandler(vm_base=env_vars.get("VM_DIR"),
-                                                               image_base=env_vars.get("IMAGE_DIR"))
+    image_storage_handler = FileSystemBasedImageStorageHandler(vm_base=env_vars.get("VM_DIR", "/tmp/ucloud-vms"),
+                                                               image_base=env_vars.get("IMAGE_DIR", "/tmp/ucloud-images"))
 elif __storage_backend == "ceph":
     image_storage_handler = CEPHBasedImageStorageHandler(vm_base="ssd", image_base="ssd")
 else: