diff --git a/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target b/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target
index dbed29e041..d68b4655b7 100644
--- a/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target
+++ b/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target
@@ -15,9 +15,7 @@ PORTAGE_BINHOST="
 "
 
 # Recommended MARCH_TUNE, CFLAGS, etc.
-# We assume that our 64bit baseline CPU supports at least
-# MMX, SSE, SSE2, and SSE3.
-MARCH_TUNE="-march=x86-64 -msse3"
+MARCH_TUNE=""
 
 # Allow a board to override or define additional settings.
 CFLAGS="-O2 -pipe ${MARCH_TUNE} -g"