diff --git a/clouddriver-appengine/src/main/groovy/com/netflix/spinnaker/clouddriver/appengine/model/AppEngineLoadBalancer.groovy b/clouddriver-appengine/src/main/groovy/com/netflix/spinnaker/clouddriver/appengine/model/AppEngineLoadBalancer.groovy
index 5e8ab59c983..8e432cf0ff6 100644
--- a/clouddriver-appengine/src/main/groovy/com/netflix/spinnaker/clouddriver/appengine/model/AppEngineLoadBalancer.groovy
+++ b/clouddriver-appengine/src/main/groovy/com/netflix/spinnaker/clouddriver/appengine/model/AppEngineLoadBalancer.groovy
@@ -62,16 +62,21 @@ class AppEngineLoadBalancer implements LoadBalancer, Serializable {
 
       def detachedInstances = serverGroup.isDisabled() ? serverGroup.instances?.collect { it.name } ?: [] : []
 
-      new LoadBalancerServerGroup(
+      new AppEngineLoadBalancerServerGroup(
         name: serverGroup.name,
         region: serverGroup.region,
         isDisabled: serverGroup.isDisabled(),
+        allowsGradualTrafficMigration: serverGroup.allowsGradualTrafficMigration,
         instances: instances as Set,
         detachedInstances: detachedInstances as Set
       )
     } as Set
     null
   }
+
+  static class AppEngineLoadBalancerServerGroup extends LoadBalancerServerGroup {
+    Boolean allowsGradualTrafficMigration
+  }
 }
 
 @AutoClone