diff --git a/weld/toolchain/gcc/arch/amd64.mk b/weld/toolchain/gcc/arch/amd64.mk
new file mode 100644
index 0000000..8b4b0d1
--- /dev/null
+++ b/weld/toolchain/gcc/arch/amd64.mk
@@ -0,0 +1,10 @@
+# Copyright 2015 Andrew Gottemoller.
+#
+# This software is a copyrighted work licensed under the terms of the
+# Weld license.  Please consult the file "WELD_LICENSE" for
+# details.
+
+# This makefile defines settings for the amd64 architecture
+
+
+compiler_flag_list := -march=x86-64 $(compiler_flag_list)