diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 2c839de..ee30951 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -2771,10 +2771,10 @@ class ComputeManager(manager.Manager):
                 LOG.info(_LI("disk not on shared storage, rebuilding from:"
                                 " '%s'"), str(image_ref))
 
-        if image_ref:
-            image_meta = self.image_api.get(context, image_ref)
-        else:
-            image_meta = {}
+        if not image_ref:
+            image_ref = instance.image_ref or {}
+
+        image_meta = self.image_api.get(context, image_ref)
 
         # This instance.exists message should contain the original
         # image_ref, not the new one.  Since the DB has been updated