diff --git a/update_chroot b/update_chroot
index 9868484..15e1158 100755
--- a/update_chroot
+++ b/update_chroot
@@ -140,7 +140,8 @@
 # Install post cross packages if binary pkgs are available.
 if [ "${FLAGS_usepkg}" -eq "${FLAGS_TRUE}" ]; then
   # Use --usepkgonly to ensure that packages are not built from source.
-  EMERGE_FLAGS=( -uNv --with-bdeps=y --oneshot --getbinpkg --deep --usepkgonly )
+  EMERGE_FLAGS=( -uNv --with-bdeps=y --oneshot --getbinpkg --deep )
+  EMERGE_FLAGS+=( --usepkgonly --rebuilt-binaries=n )
   EMERGE_FLAGS+=(
     $("${CHROMITE_BIN}/cros_setup_toolchains" --show-packages host-post-cross)
   )
@@ -148,7 +149,8 @@
 
   # Install nobdeps packages only when binary pkgs are available, since we don't
   # want to accidentally pull in build deps for a rebuild.
-  EMERGE_FLAGS=( -uNv --with-bdeps=n --oneshot --getbinpkg --deep --usepkgonly )
+  EMERGE_FLAGS=( -uNv --with-bdeps=n --oneshot --getbinpkg --deep )
+  EMERGE_FLAGS+=( --usepkgonly --rebuilt-binaries=n )
   info_run sudo -E "${EMERGE_CMD}" "${EMERGE_FLAGS[@]}" \
     virtual/target-sdk-nobdeps
 fi