diff --git a/stages/org.osbuild.mkfs.btrfs b/stages/org.osbuild.mkfs.btrfs
index b259a5f1..46a8cc15 100755
--- a/stages/org.osbuild.mkfs.btrfs
+++ b/stages/org.osbuild.mkfs.btrfs
@@ -18,7 +18,7 @@ import osbuild.api
 SCHEMA_2 = r"""
 "devices": {
   "type": "object",
-  "additionalProperties": false,
+  "additionalProperties": true,
   "required": ["device"],
   "properties": {
     "device": {
diff --git a/stages/org.osbuild.mkfs.ext4 b/stages/org.osbuild.mkfs.ext4
index bb7b438a..57b875cf 100755
--- a/stages/org.osbuild.mkfs.ext4
+++ b/stages/org.osbuild.mkfs.ext4
@@ -18,7 +18,7 @@ import osbuild.api
 SCHEMA_2 = r"""
 "devices": {
   "type": "object",
-  "additionalProperties": false,
+  "additionalProperties": true,
   "required": ["device"],
   "properties": {
     "device": {
diff --git a/stages/org.osbuild.mkfs.fat b/stages/org.osbuild.mkfs.fat
index 9e76348d..851a09f1 100755
--- a/stages/org.osbuild.mkfs.fat
+++ b/stages/org.osbuild.mkfs.fat
@@ -18,7 +18,7 @@ import osbuild.api
 SCHEMA_2 = r"""
 "devices": {
   "type": "object",
-  "additionalProperties": false,
+  "additionalProperties": true,
   "required": ["device"],
   "properties": {
     "device": {