diff --git a/build.sh b/build.sh
index c27edad..ab332a7 100644
--- a/build.sh
+++ b/build.sh
@@ -256,6 +256,12 @@ cp bin2fex $DEST/output/sdcard/usr/bin/
 cp nand-part $DEST/output/sdcard/usr/bin/
 
 # cleanup 
+# unmount proc, sys and dev from chroot
+umount $DEST/output/sdcard/dev/pts
+umount $DEST/output/sdcard/dev
+umount $DEST/output/sdcard/proc
+umount $DEST/output/sdcard/sys
+
 rm $DEST/output/sdcard/usr/bin/qemu-arm-static 
 # umount images 
 umount $DEST/output/sdcard/