diff --git a/iof.iuml b/iof.iuml
index 302cf7c..98c08bb 100644
--- a/iof.iuml
+++ b/iof.iuml
@@ -1,5 +1,5 @@
 @startuml iof
-!include https://raw.githubusercontent.com/iofoundry/ontopuml/main/ontologyv2.iuml
+!include https://raw.githubusercontent.com/iofoundry/ontopuml/refs/heads/main/ontologyv2.iuml
 hide circle
 skinparam class{
  BackgroundColor DFA702