diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1845483..1331529 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -52,6 +52,7 @@ jobs:
           echo "VCPKG_INSTALLATION_ROOT=${VCPKG_INSTALLATION_ROOT}" >> "$GITHUB_ENV"
           echo "CMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}" >> "$GITHUB_ENV"
           echo "CMAKE_OSX_ARCHITECTURES=${CMAKE_OSX_ARCHITECTURES}" >> "$GITHUB_ENV"
+          echo "ARCHFLAGS=-arch ${CMAKE_OSX_ARCHITECTURES}" >> "$GITHUB_ENV"
 
           # Fix: cibuildhweel cannot interpolate env variables.
           CONFIG_SETTINGS="cmake.define.CMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}"