diff --git a/vmm/src/vm.rs b/vmm/src/vm.rs
index a89de5bbc..542754582 100755
--- a/vmm/src/vm.rs
+++ b/vmm/src/vm.rs
@@ -676,6 +676,7 @@ impl Vm {
         self.devices
             .notify_hotplug(HotPlugNotificationType::CPUDevicesChanged)
             .map_err(Error::DeviceManager)?;
+        self.config.lock().unwrap().cpus.boot_vcpus = desired_vcpus;
         Ok(())
     }