diff --git a/implementation/vm/instance.py b/implementation/vm/instance.py
index 47ed418..9d91ad9 100644
--- a/implementation/vm/instance.py
+++ b/implementation/vm/instance.py
@@ -197,7 +197,7 @@ class OSVirtualMachineManager(InstanceInterface, OpenStackConnection):
         else:
             image_id = server.image["id"]
         return Instance(id=server.id,
-                        flavor=server.flavor["id"],
+                        flavor=server.flavor_id,
                         name=server.name,
                         image_id=image_id,
                         disks=server.attached_volumes,