diff --git a/stages/org.osbuild.containers.storage.conf b/stages/org.osbuild.containers.storage.conf
index 64524a56..f2f89ab1 100755
--- a/stages/org.osbuild.containers.storage.conf
+++ b/stages/org.osbuild.containers.storage.conf
@@ -87,6 +87,10 @@ SCHEMA = r"""
       "/usr/share/containers/storage.conf"
     ]
   },
+  "filebase": {
+    "type": "string",
+    "description": "Read the base configuration from this file."
+  },
   "comment": {
     "type": "array",
     "items": {
@@ -166,14 +170,24 @@ def main(tree, options):
     location = options.get("filename", DEFAULT_LOCATION)
     config = options["config"]
     comment = options.get("comment", [])
+    filebase = options.get("filebase")
 
     path = os.path.join(tree, location.lstrip("/"))
     data = {}
 
-    with contextlib.suppress(FileNotFoundError):
-        with open(path, "r", encoding="utf8") as f:
+    # if a filebase was specified, we use it as base
+    if filebase:
+        with open(filebase, "r", encoding="utf8") as f:
             data = toml.load(f)
 
+    # if the target exists, we merge it
+    with contextlib.suppress(FileNotFoundError):
+        with open(path, "r", encoding="utf8") as f:
+            have = toml.load(f)
+
+            merge_config("storage", data, have)
+
+    # now merge our configuration into data
     merge_config("storage", data, config)
 
     with open(path, "w", encoding="utf8") as f: