diff --git a/.github/workflows/build_wheels.yml b/.github/workflows/build_wheels.yml
index 2987064..d0a55e0 100644
--- a/.github/workflows/build_wheels.yml
+++ b/.github/workflows/build_wheels.yml
@@ -49,7 +49,7 @@ jobs:
             name: wheelhouse
             path: wheelhouse
         - run: python -m pip install --find-links wheelhouse colourtime
-          shell: bash
+        - run: python -m pip install -U --no-index --find-links wheelhouse colourtime
         - run: python -c 'import colourtime'
     build_sdist:
         name: Build source distribution