diff --git a/tools/python/xen/xend/XendConfig.py b/tools/python/xen/xend/XendConfig.py
index 9896254f32..af2971a870 100644
--- a/tools/python/xen/xend/XendConfig.py
+++ b/tools/python/xen/xend/XendConfig.py
@@ -390,11 +390,16 @@ class XendConfig(dict):
         if self.get('vcpus_number') != None:
             self['vcpu_avail'] = (1 << self['vcpus_number']) - 1
 
+    def _uuid_sanity_check(self):
+        """Make sure UUID is in proper string format with hyphens."""
+        self['uuid'] = uuid.toString(uuid.fromString(self['uuid']))
+
     def validate(self):
         self._memory_sanity_check()
         self._actions_sanity_check()
         self._builder_sanity_check()
         self._vcpus_sanity_check()
+        self._uuid_sanity_check()
 
     def _dominfo_to_xapi(self, dominfo):
         self['domid'] = dominfo['domid']