diff --git a/.github/workflows/ci-py-only.yml b/.github/workflows/ci-py-only.yml
index 27748a19de..ee4af80f3d 100644
--- a/.github/workflows/ci-py-only.yml
+++ b/.github/workflows/ci-py-only.yml
@@ -46,6 +46,8 @@ jobs:
           
       - name: ccache
         uses: hendrikmuhs/ccache-action@v1
+        with:
+          key: ${GITHUB_WORKFLOW}
 
       - name: Build ifcopenshell
         run: |
@@ -62,7 +64,7 @@ jobs:
                -DPYTHON_INCLUDE_DIR:PATH=/usr/include/python3.8 \
                -DPYTHON_LIBRARY:FILEPATH=/usr/lib/x86_64-linux-gnu/libpython3.8.so \
                -DCOLLADA_SUPPORT=Off \
-               "-DSCHEMA_VERSIONS=2x3;4" \
+               "-DSCHEMA_VERSIONS=2x3;4;4x3_add1" \
                -DBUILD_CONVERT=Off \
                -DGLTF_SUPPORT=On \
                -DJSON_INCLUDE_DIR=/usr/include \