diff --git a/sdk_lib/make_chroot.sh b/sdk_lib/make_chroot.sh
index 012cbb06d3..09cc500385 100755
--- a/sdk_lib/make_chroot.sh
+++ b/sdk_lib/make_chroot.sh
@@ -368,7 +368,7 @@ info "Setting up mounts..."
 # Set up necessary mounts and make sure we clean them up on exit.
 sudo mkdir -p "${FLAGS_chroot}/${CHROOT_TRUNK}" "${FLAGS_chroot}/run"
 PREBUILT_SETUP="$FLAGS_chroot/etc/make.conf.prebuilt_setup"
-if [[ -z "$IGNORE_PREFLIGHT_BINHOST" ]]; then
+if [[ -n "$IGNORE_PREFLIGHT_BINHOST" ]]; then
   echo 'PORTAGE_BINHOST="$FULL_BINHOST"'
 fi | sudo_clobber "$PREBUILT_SETUP"
 
diff --git a/update_chroot b/update_chroot
index 4283474d56..8a271c3959 100755
--- a/update_chroot
+++ b/update_chroot
@@ -39,10 +39,8 @@ ${SCRIPTS_DIR}/run_chroot_version_hooks
 
 PREBUILT_SETUP="/etc/make.conf.prebuilt_setup"
 if [[ -n "$IGNORE_PREFLIGHT_BINHOST" ]]; then
-  echo 'PORTAGE_BINHOST="$FULL_BINHOST"' | sudo_clobber "$PREBUILT_SETUP"
-elif [[ -s "$PREBUILT_SETUP" ]]; then
-  sudo_clobber "$PREBUILT_SETUP" < /dev/null
-fi
+  echo 'PORTAGE_BINHOST="$FULL_BINHOST"'
+fi | sudo_clobber "$PREBUILT_SETUP"
 
 info "Updating chroot"