diff --git a/lib/objects.py b/lib/objects.py
index f8667e34361ab7573997815b77c84f9dfed24b0a..e3ff4ac4e8abada4dea540faf19f16cdb9e049c7 100644
--- a/lib/objects.py
+++ b/lib/objects.py
@@ -499,6 +499,8 @@ class ConfigData(ConfigObject):
         self.cluster.drbd_usermode_helper = constants.DEFAULT_DRBD_HELPER
     if self.networks is None:
       self.networks = {}
+    for network in self.networks.values():
+      network.UpgradeConfig()
 
 
 class NIC(ConfigObject):