diff --git a/.github/workflows/cbuild.yml b/.github/workflows/cbuild.yml
new file mode 100644
index 0000000..3b5058c
--- /dev/null
+++ b/.github/workflows/cbuild.yml
@@ -0,0 +1,68 @@
+name: cBuild
+
+# Build on every branch push, tag push, and pull request change:
+#on: [push]
+# Alternatively, to publish when a (published) GitHub Release is created, use the following:
+on:
+  push:
+    branches:
+      - main
+      - develop
+
+jobs:
+  build_wheels:
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-13, macos-14]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@v2.19.1
+        env:
+          # Disable building PyPy wheels on all platforms
+          CIBW_SKIP: pp*
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: cibw-wheels-${{ matrix.os }}-${{ strategy.job-index }}
+          path: ./wheelhouse/*.whl
+
+  build_sdist:
+    name: Build source distribution
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build sdist
+        run: pipx run build --sdist
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: cibw-sdist
+          path: dist/*.tar.gz
+
+  upload_pypi:
+    needs: [build_wheels, build_sdist]
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write
+    # or, alternatively, upload to PyPI on every tag starting with 'v' (remove on: release above to use this)
+    # if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          # unpacks all CIBW artifacts into dist/
+          pattern: cibw-*
+          path: dist
+          merge-multiple: true
+
+      - uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          user: __token__
+          password: ${{ secrets.test_pypi_password }}
+          repository_url: https://test.pypi.org/legacy/
\ No newline at end of file
diff --git a/.github/workflows/cibuild-pypi.yml b/.github/workflows/cibuild-pypi.yml
index b690acd..b7e2043 100644
--- a/.github/workflows/cibuild-pypi.yml
+++ b/.github/workflows/cibuild-pypi.yml
@@ -1,4 +1,4 @@
-name: Build and upload to PyPI
+name: cBuild and upload to PyPI
 
 # Build on every branch push, tag push, and pull request change:
 #on: [push]
@@ -19,45 +19,52 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-13, macos-14]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Build wheels
         uses: pypa/cibuildwheel@v2.19.1
+        env:
+          # Disable building PyPy wheels on all platforms
+          CIBW_SKIP: pp*
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
+          name: cibw-wheels-${{ matrix.os }}-${{ strategy.job-index }}
           path: ./wheelhouse/*.whl
 
   build_sdist:
     name: Build source distribution
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Build sdist
         run: pipx run build --sdist
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
+          name: cibw-sdist
           path: dist/*.tar.gz
 
   upload_pypi:
     needs: [build_wheels, build_sdist]
     runs-on: ubuntu-latest
-    # upload to PyPI on every tag starting with 'v'
-    #if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
-    # alternatively, to publish when a GitHub Release is created, use the following rule:
-    # if: github.event_name == 'release' && github.event.action == 'published'
+    environment: pypi
+    permissions:
+      id-token: write
+    if: github.event_name == 'release' && github.event.action == 'published'
+    # or, alternatively, upload to PyPI on every tag starting with 'v' (remove on: release above to use this)
+    # if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
-          # unpacks default artifact into dist/
-          # if `name: artifact` is omitted, the action will create extra parent dir
-          name: artifact
+          # unpacks all CIBW artifacts into dist/
+          pattern: cibw-*
           path: dist
+          merge-multiple: true
 
-      - uses: pypa/gh-action-pypi-publish@v1.5.0
+      - uses: pypa/gh-action-pypi-publish@release/v1
         with:
-          user: ${{ secrets.pypi_username }}
+          user: __token__
           password: ${{ secrets.pypi_password }}
           repository_url: https://upload.pypi.org/legacy/
\ No newline at end of file
diff --git a/setup.py b/setup.py
index a501ba1..8cdaac9 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
     name="spectresc",
     maintainer="Marco C Lam",
     maintainer_email="mlam@roe.ac.uk",
-    version="1.0.3",
+    version="1.0.4",
     install_requires=[
         "numpy",
     ],
@@ -22,7 +22,6 @@
         "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
         "Programming Language :: C",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",