diff --git a/kernels/optimized/lib_defs.bzl b/kernels/optimized/lib_defs.bzl
index f4c103c0a0f..11a5f3a966b 100644
--- a/kernels/optimized/lib_defs.bzl
+++ b/kernels/optimized/lib_defs.bzl
@@ -156,8 +156,11 @@ def define_libs():
                     ],
                 ),
             ],
-            fbobjc_compiler_flags = [
-                "-march=armv8+bf16",
+            fbobjc_platform_compiler_flags = [
+                (
+                    ".*arm64.*",
+                    ["-march=armv8+bf16"],
+                ),
             ],
             fbobjc_exported_preprocessor_flags = [
                 "-DET_BUILD_WITH_BLAS",