diff --git a/.github/workflows/build-ci.yml b/.github/workflows/build-ci.yml
index 29dafaf4a..4091d3d8d 100644
--- a/.github/workflows/build-ci.yml
+++ b/.github/workflows/build-ci.yml
@@ -197,14 +197,14 @@ jobs:
 
     - name: Archive C++ test logs
       if: ${{ failure() && !(matrix.enable-mpi == false && matrix.python-version == 3.9) }}
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: cpp-tests-mpi-${{ matrix.enable-mpi }}-log
         path: ${{ github.workspace }}/build/meep-${{ env.MEEP_VERSION }}/_build/sub/tests/test-suite.log
 
     - name: Archive Python test logs
       if: ${{ failure() && !(matrix.enable-mpi == false && matrix.python-version == 3.9) }}
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: py${{ matrix.python-version }}-tests-mpi-${{ matrix.enable-mpi }}-log
         path: ${{ github.workspace }}/build/meep-${{ env.MEEP_VERSION }}/_build/sub/python/test-suite.log
diff --git a/.github/workflows/build-san.yml b/.github/workflows/build-san.yml
index 52d12ec97..50f8f794c 100644
--- a/.github/workflows/build-san.yml
+++ b/.github/workflows/build-san.yml
@@ -51,7 +51,7 @@ jobs:
     - name: Run sanitizer
       run: make -j$(nproc) check
     - name: Archive test logs
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       if: failure()
       with:
         name: ${{ matrix.name-suffix }}-log