diff --git a/.github/workflows/build_cibuildwheel.yml b/.github/workflows/build_cibuildwheel.yml
index 9639bf3..d8d6da8 100644
--- a/.github/workflows/build_cibuildwheel.yml
+++ b/.github/workflows/build_cibuildwheel.yml
@@ -45,9 +45,10 @@ jobs:
         env:
           CIBW_ARCHS: auto64
           # CIBW_ARCHS_MACOS: "universal2"
-          CIBW_ENVIRONMENT_MACOS: MACOSX_DEPLOYMENT_TARGET=11.0
+          CIBW_ENVIRONMENT_MACOS: MACOSX_DEPLOYMENT_TARGET=11.0 CMAKE_BUILD_PARALLEL_LEVEL='1'
           CIBW_TEST_COMMAND: python -c "import teqp"
           CIBW_ENVIRONMENT_LINUX: CXXFLAGS='-fconcepts' CMAKE_BUILD_PARALLEL_LEVEL='1'
+          CIBW_ENVIRONMENT_WINDOW: CMAKE_BUILD_PARALLEL_LEVEL='1'
           CIBW_BUILD_VERBOSITY_WINDOWS: 2
           CIBW_SKIP: "*pypy* *pp* *cp36* *cp37* *cp38* *musl*"