diff --git a/source/boot/x86/images.sh b/source/boot/x86/images.sh
index 79107431a..109e59ded 100644
--- a/source/boot/x86/images.sh
+++ b/source/boot/x86/images.sh
@@ -154,7 +154,7 @@ EOF
 
 	# determine size and add a bit of space
 	size=`du -sm $tmp | cut -f 1`
-	size=$((size + $size / 2))
+	size=$((size + $size))
 
 	# create disk
 	./tools/disk.py create --offset 2048 --part ext3 $size $tmp $1/usb.img