diff --git a/tools/python/xen/xend/XendConfig.py b/tools/python/xen/xend/XendConfig.py
index 98f1f572fa..da0deb3bb0 100644
--- a/tools/python/xen/xend/XendConfig.py
+++ b/tools/python/xen/xend/XendConfig.py
@@ -142,6 +142,7 @@ ROUNDTRIPPING_CONFIG_ENTRIES = [
     ('uuid',       str),
     ('vcpus',      int),
     ('vcpu_avail', int),
+    ('cpu_cap',    int),
     ('cpu_weight', int),
     ('memory',     int),
     ('shadow_memory', int),