diff --git a/gentooup.sh b/gentooup.sh
index 2f56f69..8a05709 100755
--- a/gentooup.sh
+++ b/gentooup.sh
@@ -1,7 +1,13 @@
 #!/bin/bash
 
+LOCKFILE=/usr/portage/gentooup.lock
+exec {FD_LOCK}<>"$LOCKFILE"
+if ! flock -x -w 60 "$FD_LOCK" ; then
+  echo "Could not acquire lock for $LOCKFILE"
+  exit 1
+fi
 
-PORTAGE_OPTIONS=("--keep-going" "--autounmask-write" "--binpkg-respect-use=y" "--binpkg-changed-deps=y" "--autounmask-continue")
+PORTAGE_OPTIONS=("--keep-going" "--autounmask-write" "--binpkg-changed-deps=y" "--autounmask-continue")
 
 PORTAGE_UPGRADE_OPTIONS=("-vuNDk")