diff --git a/gentoostrap.sh b/gentoostrap.sh
index 84ddee8..47fe4df 100755
--- a/gentoostrap.sh
+++ b/gentoostrap.sh
@@ -195,11 +195,15 @@ build-gentoo() {
 	popd
 	log "Pivoting to container for more setup"
 	cp "$0" "$_optdest/gentoostrap.sh"
-	mount --types proc /proc "$_optdest/proc"
-	mount --rbind /sys "$_optdest/sys"
-	mount --make-rslave "$_optdest/sys"
-	mount --rbind /dev "$_optdest/dev"
-	mount --make-rslave "$_optdest/dev"
+	if ! grep -qs "$_optdest/proc " /proc/mounts; then
+		mount --types proc /proc "$_optdest/proc"
+	fi
+	for dir in sys dev; do
+		if ! grep -qs "$_optdest/$mount " /proc/mounts; then
+			mount --rbind /$mount "$_optdest/$mount"
+			mount --make-rslave "$_optdest/$mount"
+		fi
+	done
 	chroot "$_optdest" /gentoostrap.sh -c
 	chroot "$_optdest" /gentoostrap.sh -d
 	log "Configuration complete! You should be good to reboot now."