diff --git a/action-c2a-build-win32/action.yml b/action-c2a-build-win32/action.yml
index 8f3451c..f8a3f90 100644
--- a/action-c2a-build-win32/action.yml
+++ b/action-c2a-build-win32/action.yml
@@ -59,6 +59,7 @@ runs:
         cmake -B ./build \
           -G "${{ inputs.cmake_generator }}" \
           -DBUILD_C2A_AS_CXX=OFF \
+          -DC2A_BUILD_AS_CXX=OFF \
           ${{ inputs.cmake_flags }}
 
     - name: CMake as C++
@@ -69,6 +70,7 @@ runs:
         cmake -B ./build \
           -G "${{ inputs.cmake_generator }}" \
           -DBUILD_C2A_AS_CXX=ON \
+          -DC2A_BUILD_AS_CXX=ON \
           ${{ inputs.cmake_flags }}
 
     - name: Build
diff --git a/action-c2a-build/action.yml b/action-c2a-build/action.yml
index 95626ba..cbbeac2 100644
--- a/action-c2a-build/action.yml
+++ b/action-c2a-build/action.yml
@@ -79,6 +79,7 @@ runs:
           -G "${{ inputs.cmake_generator }}" \
           -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
           -DBUILD_C2A_AS_CXX=OFF \
+          -DC2A_BUILD_AS_CXX=OFF \
           ${{ (inputs.sils_mockup && '-DUSE_SILS_MOCKUP=ON') || '' }} \
           ${{ inputs.cmake_flags }}
 
@@ -95,6 +96,7 @@ runs:
           -G "${{ inputs.cmake_generator }}" \
           -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
           -DBUILD_C2A_AS_CXX=ON \
+          -DC2A_BUILD_AS_CXX=ON \
           -DUSE_SCI_COM_WINGS=OFF \
           ${{ inputs.cmake_flags }}