diff --git a/gentooup.sh b/gentooup.sh
index 01cc347..b957c19 100755
--- a/gentooup.sh
+++ b/gentooup.sh
@@ -14,6 +14,9 @@ CHROOTED=0
 
 SYNC_COMMAND="emaint sync -a"
 
+BACKTRACK_INTERACTIVE=30 # 10 is the default
+BACKTRACK_BATCH=200
+
 int_handler() {
   exit 0
 }
@@ -98,6 +101,14 @@ while [[ $# -gt 0 ]]; do
     esac
   done
 
+if [[ $INTERACTIVE == 1 ]] ; then
+  BACKTRACK="$BACKTRACK_INTERACTIVE"
+else
+  BACKTRACK="$BACKTRACK_BATCH"
+fi
+
+PORTAGE_OPTIONS+=( "--backtrack=$BACKTRACK" )
+
 if [[ $CHROOTED == 1 ]] ; then
   SYNC_COMMAND=""
   for repo in helpers meskal-overlay selba ; do