diff --git a/.github/workflows/build-wheel-release-upload.yml b/.github/workflows/build-wheel-release-upload.yml
index 546bbe6..76aa3e4 100644
--- a/.github/workflows/build-wheel-release-upload.yml
+++ b/.github/workflows/build-wheel-release-upload.yml
@@ -11,6 +11,7 @@ jobs:
     uses: Billingegroup/release-scripts/.github/workflows/_build-wheel-release-upload.yml@v0
     with:
       project: diffpy.pdffit2
+      c_extension: true
     secrets:
       PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
       PAT_TOKEN: ${{ secrets.PAT_TOKEN }}