diff --git a/.github/workflows/cmake_arm.yml b/.github/workflows/cmake_arm.yml
index 52aaa71e8..0c584eb9a 100644
--- a/.github/workflows/cmake_arm.yml
+++ b/.github/workflows/cmake_arm.yml
@@ -182,7 +182,7 @@ jobs:
         run: |
           sudo apt install -y ninja-build
           python3 tools/get_deps.py ${{ matrix.family }}
-          python tools/build_cmake.py ${{ matrix.family }} -DCMAKE_BUILD_TYPE=MinSizeRel
+          python tools/build_cmake.py ${{ matrix.family }} -DTOOLCHAIN=clang -DCMAKE_BUILD_TYPE=MinSizeRel
         env:
           PICO_SDK_PATH: ${{ github.workspace }}/pico-sdk