diff --git a/pyproject.toml b/pyproject.toml
index 1a23b4b7490..4b5683cffcc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -167,6 +167,8 @@ MYPYC_DEBUG_LEVEL = "0"
 # from source also doesn't work.
 AIOHTTP_NO_EXTENSIONS = "1"
 
+MACOSX_DEPLOYMENT_TARGET = """$(python -c 'import sysconfig; print(sysconfig.get_config_var("MACOSX_DEPLOYMENT_TARGET"))')"""
+
 [tool.cibuildwheel.linux]
 before-build = [
     "yum install -y clang gcc",
@@ -176,9 +178,10 @@ before-build = [
 HATCH_BUILD_HOOKS_ENABLE = "1"
 MYPYC_OPT_LEVEL = "3"
 MYPYC_DEBUG_LEVEL = "0"
+AIOHTTP_NO_EXTENSIONS = "1"
+
 # Black needs Clang to compile successfully on Linux.
 CC = "clang"
-AIOHTTP_NO_EXTENSIONS = "1"
 
 [tool.isort]
 atomic = true