diff --git a/validator/schema/upsun.json b/validator/schema/upsun.json
index 11e536d..3e8557e 100644
--- a/validator/schema/upsun.json
+++ b/validator/schema/upsun.json
@@ -723,6 +723,7 @@
           },
           {
             "required": [
+              "type",
               "stack"
             ]
           }
diff --git a/validator/validator_test.go b/validator/validator_test.go
index 8c06723..0673c3d 100644
--- a/validator/validator_test.go
+++ b/validator/validator_test.go
@@ -138,6 +138,7 @@ services:
 						Data: []byte(`
 applications:
   app1:
+    type: "composable:25.05"
     stack:
       - "php@8.3":
         extensions: