diff --git a/.github/workflows/clang-format.yml b/.github/workflows/clang-format.yml
index e65588e..b3cd6b5 100644
--- a/.github/workflows/clang-format.yml
+++ b/.github/workflows/clang-format.yml
@@ -15,24 +15,24 @@ jobs:
   format-check:
     runs-on:
       group: default
+    env:
+      CLANG_RELEASE: 18
     strategy:
       fail-fast: false
-      matrix:
-        release:
-          - 18
-    container: libfn/ci-build-clang:${{ matrix.release }}
+    container: libfn/ci-build-clang:${{ env.CLANG_RELEASE }}
     steps:
     - name: Check version
       run: |
-        clang-format --version | grep -F "clang-format version ${{ matrix.release }}"
+        clang-format --version | grep -F "clang-format version ${CLANG_RELEASE}"
 
     - uses: actions/checkout@v4
 
     - name: Format source files
-      run: find include tests -type f \( -name '*.cpp' -o -name '*.hpp' -o -name '*.ipp' \) -print0 | xargs -0 clang-format-${{ matrix.release }} -i
+      run: find include tests -type f \( -name '*.cpp' -o -name '*.hpp' -o -name '*.ipp' \) -print0 | xargs -0 clang-format-${CLANG_RELEASE} -i
 
     - name: Check for differences
       id: assert
+      shell: bash
       run: |
         set -o pipefail
         git diff --exit-code | tee "clang-format.patch"
@@ -65,6 +65,6 @@ jobs:
              in your repo, commit, and push.
       run: |
         echo "${PREAMBLE}"
-        clang-format-${{ matrix.release }} --version
+        clang-format-${CLANG_RELEASE} --version
         echo "${SUGGESTION}"
         exit 1