diff --git a/.github/workflows/build-publish-pypi.yml b/.github/workflows/build-publish-pypi.yml
index 57303ee0..8359da62 100644
--- a/.github/workflows/build-publish-pypi.yml
+++ b/.github/workflows/build-publish-pypi.yml
@@ -50,8 +50,32 @@ jobs:
           path: dist/*.tar.gz
           retention-days: 1
 
+  publish-to-testpypi:
+    name: Upload to TestPyPI
+    needs: [build_wheels, build_sdist]
+    runs-on: ubuntu-latest
+
+    environment:
+      name: testpypi
+      url: https://test.pypi.org/p/xraylib
+
+    permissions:
+      id-token: write  # IMPORTANT: mandatory for trusted publishing
+
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          # unpacks all CIBW artifacts into dist/
+          pattern: cibw-*
+          path: dist
+          merge-multiple: true
+      - name: Publish distribution 📦 to TestPyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          repository-url: https://test.pypi.org/legacy/
+
   upload_pypi:
-    name: Upload to pypi
+    name: Upload to PyPI
     needs: [build_wheels, build_sdist]
     runs-on: ubuntu-latest
     environment: pypi