From 33995be9634d1d37d90e47a4530b532e3979a440 Mon Sep 17 00:00:00 2001
From: Will Dean <wd60622@gmail.com>
Date: Mon, 5 Aug 2024 21:53:30 +0200
Subject: [PATCH] change of syntax

---
 .github/workflows/uml.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/uml.yml b/.github/workflows/uml.yml
index a0b672de..e241c21f 100644
--- a/.github/workflows/uml.yml
+++ b/.github/workflows/uml.yml
@@ -18,7 +18,7 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
-          ref: ${GITHUB_HEAD_REF:-main}
+          ref: ${{ github.head_ref || 'main' }}
 
       - name: Set up Python
         uses: actions/setup-python@v2