diff --git a/.github/workflows/regression_tests.yml b/.github/workflows/regression_tests.yml
index 016a07165..9c4a9b772 100644
--- a/.github/workflows/regression_tests.yml
+++ b/.github/workflows/regression_tests.yml
@@ -40,7 +40,7 @@ jobs:
         with:
           repository: ecmwf-ifs/ecwam
           path: ecwam
-          ref: develop
+          ref: develop-1.3
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5