diff --git a/vmm/src/api/openapi/cloud-hypervisor.yaml b/vmm/src/api/openapi/cloud-hypervisor.yaml
index dee8bdbf0..a2392f988 100644
--- a/vmm/src/api/openapi/cloud-hypervisor.yaml
+++ b/vmm/src/api/openapi/cloud-hypervisor.yaml
@@ -578,6 +578,9 @@ components:
       description: Virtual machine configuration
 
     CpuAffinity:
+      required:
+        - vcpu
+        - host_cpus
       type: object
       properties:
         vcpu: