diff --git a/util/xcompile/xcompile b/util/xcompile/xcompile
index 8eea8cb94d..9019788749 100644
--- a/util/xcompile/xcompile
+++ b/util/xcompile/xcompile
@@ -106,6 +106,11 @@ detect_special_flags() {
 		# Use bfd linker instead of gold if available:
 		testcc "$CC"   "$CFLAGS -fuse-ld=bfd" &&
 			CFLAGS="$CFLAGS -fuse-ld=bfd" && LINKER_SUFFIX_i386='.bfd'
+		# Always build for i686 -- no sse/mmx instructions since SMM
+		# modules are compiled using these flags. Note that this
+		# doesn't prevent a project using xcompile to explicitly
+		# specify -mmsse, etc flags.
+		CFLAGS="$CFLAGS  -march=i686"
 		;;
 	arm )
 		ARMFLAGS=""