diff --git a/.github/actions/wait-for-pypi-version/action.yaml b/.github/actions/wait-for-pypi-version/action.yaml
new file mode 100644
index 0000000..f27bff1
--- /dev/null
+++ b/.github/actions/wait-for-pypi-version/action.yaml
@@ -0,0 +1,86 @@
+name: 'Wait for PyPI version'
+description: 'Wait for a specific package version to become available on PyPI or TestPyPI'
+inputs:
+  repository:
+    description: 'PyPI repository type: "pypi" or "testpypi"'
+    required: true
+  package:
+    description: 'Package name'
+    required: true
+  version:
+    description: 'Package version to wait for'
+    required: true
+  max_attempts:
+    description: 'Maximum number of retry attempts'
+    required: false
+    default: '30'
+  wait_seconds:
+    description: 'Seconds to wait between attempts'
+    required: false
+    default: '10'
+
+runs:
+  using: composite
+  steps:
+    - name: Install requests
+      shell: bash
+      run: |
+        python -m pip install --upgrade pip
+        pip install requests
+
+    - name: Wait for version to be available
+      shell: bash
+      env:
+        REPOSITORY: ${{ inputs.repository }}
+        PACKAGE: ${{ inputs.package }}
+        VERSION: ${{ inputs.version }}
+        MAX_ATTEMPTS: ${{ inputs.max_attempts }}
+        WAIT_SECONDS: ${{ inputs.wait_seconds }}
+      run: |
+        if [ "$REPOSITORY" = "testpypi" ]; then
+          API_URL="https://test.pypi.org/pypi/$PACKAGE/json"
+          REPO_NAME="TestPyPI"
+        elif [ "$REPOSITORY" = "pypi" ]; then
+          API_URL="https://pypi.org/pypi/$PACKAGE/json"
+          REPO_NAME="PyPI"
+        else
+          echo "ERROR: repository must be 'pypi' or 'testpypi', got '$REPOSITORY'"
+          exit 1
+        fi
+
+        # Export shell variables so Python can access them via os.environ
+        export API_URL REPO_NAME
+
+        ATTEMPT=0
+        while [ $ATTEMPT -lt $MAX_ATTEMPTS ]; do
+          if python -c "
+            import os
+            import requests
+            import sys
+            try:
+              api_url = os.environ['API_URL']
+              version = os.environ['VERSION']
+              repo_name = os.environ['REPO_NAME']
+              r = requests.get(api_url, timeout=10)
+              r.raise_for_status()
+              versions = r.json().get('releases', {})
+              print('Available versions:', list(versions.keys())[-10:])  # Show last 10 versions
+              if version in versions:
+                print(f'✓ Version {version} is available on {repo_name}')
+                sys.exit(0)
+              else:
+                print(f'✗ Version {version} is NOT available on {repo_name}')
+                sys.exit(1)
+            except Exception as e:
+              print(f'Error checking version: {e}')
+              sys.exit(1)
+          " 2>/dev/null; then
+            echo "Version $VERSION is now available on $REPO_NAME"
+            exit 0
+          fi
+          ATTEMPT=$((ATTEMPT + 1))
+          echo "Attempt $ATTEMPT/$MAX_ATTEMPTS: Version $VERSION not yet available on $REPO_NAME, waiting $WAIT_SECONDS seconds..."
+          sleep $WAIT_SECONDS
+        done
+        echo "ERROR: Version $VERSION did not become available on $REPO_NAME after $MAX_ATTEMPTS attempts"
+        exit 1
diff --git a/.github/workflows/deploy.yaml b/.github/workflows/deploy.yaml
index e1cca34..53ce330 100644
--- a/.github/workflows/deploy.yaml
+++ b/.github/workflows/deploy.yaml
@@ -21,6 +21,8 @@ jobs:
   build:
     name: Build package
     runs-on: ubuntu-latest
+    outputs:
+      version: ${{ steps.extract-version.outputs.version }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -43,6 +45,24 @@ jobs:
         run: |
           twine check dist/*
 
+      - name: Extract package version
+        id: extract-version
+        run: |
+          WHEEL_FILE=$(ls dist/*.whl)
+          # Extract version from wheel filename (format: griddataformats-VERSION-py3-none-any.whl)
+          VERSION=$(basename "$WHEEL_FILE" | sed -n 's/griddataformats-\([^-]*\)-.*/\1/p')
+          # Fallback: install wheel temporarily and get version
+          if [ -z "$VERSION" ]; then
+            # This is a bit dirty; running in a virtual environment would be cleaner.
+            # (pip install only works because our package's dependencies are easy to install.)
+            python -m pip install --upgrade pip
+            pip install "$WHEEL_FILE" --quiet
+            VERSION=$(python -c "import gridData; print(gridData.__version__)")
+            pip uninstall -y griddataformats --quiet
+          fi
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "Extracted version: $VERSION"
+
       - name: Upload dist files
         uses: actions/upload-artifact@v4
         with:
@@ -133,7 +153,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-    needs: deploy-testpypi
+    needs: [build, deploy-testpypi]
     if: |
       github.repository == 'MDAnalysis/GridDataFormats' &&
       (github.event_name == 'push' && startsWith(github.ref, 'refs/tags/'))
@@ -143,10 +163,20 @@ jobs:
         with:
           python-version: "3.14"
 
+      - name: Checkout repository for actions
+        uses: actions/checkout@v4
+
+      - name: Wait for version to be available on TestPyPI
+        uses: ./.github/actions/wait-for-pypi-version
+        with:
+          repository: testpypi
+          package: GridDataFormats
+          version: ${{ needs.build.outputs.version }}
+
       - name: Install from TestPyPI
         run: |
           python -m pip install --upgrade pip
-          pip install --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple/ GridDataFormats[test]
+          pip install --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple/ "GridDataFormats[test]==${{ needs.build.outputs.version }}"
 
       - name: Test import
         run: |
@@ -163,7 +193,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-    needs: deploy-pypi
+    needs: [build, deploy-pypi]
     if: |
       github.repository == 'MDAnalysis/GridDataFormats' &&
       (github.event_name == 'release' && github.event.action == 'published')
@@ -173,10 +203,20 @@ jobs:
         with:
           python-version: "3.14"
 
+      - name: Checkout repository for actions
+        uses: actions/checkout@v4
+
+      - name: Wait for version to be available on PyPI
+        uses: ./.github/actions/wait-for-pypi-version
+        with:
+          repository: pypi
+          package: GridDataFormats
+          version: ${{ needs.build.outputs.version }}
+
       - name: Install from PyPI
         run: |
           python -m pip install --upgrade pip
-          pip install GridDataFormats[test]
+          pip install "GridDataFormats[test]==${{ needs.build.outputs.version }}"
 
       - name: Test import
         run: |