diff --git a/.github/workflows/arm-ci.yml b/.github/workflows/arm-ci.yml
index d993e0397..3df13163f 100644
--- a/.github/workflows/arm-ci.yml
+++ b/.github/workflows/arm-ci.yml
@@ -21,5 +21,5 @@ jobs:
           cmake -S . -B build \
             -DCMAKE_TOOLCHAIN_FILE=${DEVKITPRO}/cmake/3DS.cmake
       - name: Build
-        run: make CXXFLAGS="-w -DHB_NO_MT"
+        run: make CXX_FLAGS="-w -DHB_NO_MT"
         working-directory: build