diff --git a/tripleo_common/actions/parameters.py b/tripleo_common/actions/parameters.py
index eb2b9af2b..e64ae3451 100644
--- a/tripleo_common/actions/parameters.py
+++ b/tripleo_common/actions/parameters.py
@@ -394,7 +394,7 @@ class GenerateFencingParametersAction(base.TripleOAction):
             if "ports" in node:
                 # Not all Ironic drivers present a MAC address, so we only
                 # capture it if it's present
-                mac_addr = node['ports'][0]['address']
+                mac_addr = node['ports'][0]['address'].lower()
                 node_data["host_mac"] = mac_addr
 
                 # If the MAC isn't in the hostmap, this node hasn't been