diff --git a/.github/workflows/unix.yml b/.github/workflows/unix.yml
index 0acd4d19a6..b7b2630f17 100644
--- a/.github/workflows/unix.yml
+++ b/.github/workflows/unix.yml
@@ -43,7 +43,7 @@ jobs:
         python3 -m pip install -U numpy
         sudo .github/workflows/dependencies/install_spack
     - name: Build
-      env: {CC: mpicc, CXX: mpic++, OMPI_CC: clang-10, OMPI_CXX: clang++-10, CXXFLAGS: -Werror -Wno-deprecated-declarations}
+      env: {CC: mpicc, CXX: mpic++, OMPI_CC: clang-10, OMPI_CXX: clang++-10, CXXFLAGS: -Werror -Wno-deprecated-declarations, OPENPMD_HDF5_CHUNKS: none}
       run: |
         eval $(spack env activate --sh .github/ci/spack-envs/clangtidy_nopy_ompi_h5_ad1_ad2/)
         spack install
@@ -51,8 +51,15 @@ jobs:
         mkdir build && cd build
         ../share/openPMD/download_samples.sh && chmod u-w samples/git-sample/*.h5
         export LDFLAGS="${LDFLAGS} -fsanitize=address,undefined -shared-libsan"
-        CXXFLAGS="${CXXFLAGS} -fsanitize=address,undefined -shared-libsan"
-        CXXFLAGS="${CXXFLAGS}" cmake -S .. -B . -DopenPMD_USE_MPI=ON -DopenPMD_USE_PYTHON=ON -DopenPMD_USE_HDF5=ON -DopenPMD_USE_ADIOS2=ON -DopenPMD_USE_ADIOS1=ON -DopenPMD_USE_INVASIVE_TESTS=ON -DCMAKE_VERBOSE_MAKEFILE=ON
+        export CXXFLAGS="${CXXFLAGS} -fsanitize=address,undefined -shared-libsan"
+        cmake -S .. -B .                  \
+          -DopenPMD_USE_MPI=ON            \
+          -DopenPMD_USE_PYTHON=ON         \
+          -DopenPMD_USE_HDF5=ON           \
+          -DopenPMD_USE_ADIOS2=ON         \
+          -DopenPMD_USE_ADIOS1=ON         \
+          -DopenPMD_USE_INVASIVE_TESTS=ON \
+          -DCMAKE_VERBOSE_MAKEFILE=ON
         cmake --build . --parallel 2
         export ASAN_OPTIONS=detect_stack_use_after_return=1:detect_leaks=1:check_initialization_order=true:strict_init_order=true:detect_stack_use_after_scope=1:fast_unwind_on_malloc=0
         export LSAN_OPTIONS=suppressions="$SOURCEPATH/.github/ci/sanitizer/clang/Leak.supp"