diff --git a/utils/bazel/llvm-project-overlay/llvm/config.bzl b/utils/bazel/llvm-project-overlay/llvm/config.bzl
--- a/utils/bazel/llvm-project-overlay/llvm/config.bzl
+++ b/utils/bazel/llvm-project-overlay/llvm/config.bzl
@@ -76,7 +76,8 @@
 # TODO: We should split out host vs. target here.
 llvm_config_defines = os_defines + select({
     "@bazel_tools//src/conditions:windows": native_arch_defines("X86", "x86_64-pc-win32"),
-    "@bazel_tools//src/conditions:darwin": native_arch_defines("X86", "x86_64-unknown-darwin"),
+    "@bazel_tools//src/conditions:darwin_arm64": native_arch_defines("AArch64", "arm64-apple-darwin"),
+    "@bazel_tools//src/conditions:darwin_x86_64": native_arch_defines("X86", "x86_64-unknown-darwin"),
     "@bazel_tools//src/conditions:linux_aarch64": native_arch_defines("AArch64", "aarch64-unknown-linux-gnu"),
     "//conditions:default": native_arch_defines("X86", "x86_64-unknown-linux-gnu"),
 }) + [