diff --git a/lib/hypervisor/hv_kvm.py b/lib/hypervisor/hv_kvm.py
index 290a2e866ee082757819b36592b13a7fa28ae8de..6df67df811ef5287e12a2bc57bf03f5d8d445a84 100644
--- a/lib/hypervisor/hv_kvm.py
+++ b/lib/hypervisor/hv_kvm.py
@@ -875,7 +875,7 @@ class KVMHypervisor(hv_base.BaseHypervisor):
         raise
       else:
         uid.Unlock()
-        utils.WriteFile(self._InstanceUidFile(name), data=str(uid))
+        utils.WriteFile(self._InstanceUidFile(name), data=uid.AsStr())
     else:
       self._RunKVMCmd(name, kvm_cmd, tapfds)