diff --git a/.github/workflows/check-cpp23.yml b/.github/workflows/check-cpp23.yml
index 15b16e71e4..9a634b951f 100644
--- a/.github/workflows/check-cpp23.yml
+++ b/.github/workflows/check-cpp23.yml
@@ -55,8 +55,8 @@ jobs:
       uses: actions/cache@v4
       with:
         path: ${{ env.CCACHE_DIR }}
-        key: linux-cpp23-ccache-${{ github.sha }}
-        restore-keys: linux-cpp23-ccache-
+        key: linux-cpp23-ccache-${{ matrix.idx }}-${{ github.sha }}
+        restore-keys: linux-cpp23-ccache-${{ matrix.idx }}
 
     - name: Building LAMMPS via CMake
       shell: bash