diff --git a/meta/classes/image_types.bbclass b/meta/classes/image_types.bbclass
index d286eea..aa1a785 100644
--- a/meta/classes/image_types.bbclass
+++ b/meta/classes/image_types.bbclass
@@ -82,9 +82,9 @@ runimagecmd () {
 	# The base_size gets calculated:
 	#  - initial size determined by `du -ks` of the IMAGE_ROOTFS
 	#  - then multiplied by the IMAGE_OVERHEAD_FACTOR
-	#  - then rounded up to IMAGE_ROOTFS_ALIGNMENT
-	#  - finally tested against IMAGE_ROOTFS_SIZE
-	ROOTFS_SIZE=`du -ks ${IMAGE_ROOTFS}|awk '{base_size = $1 * ${IMAGE_OVERHEAD_FACTOR} + ${IMAGE_ROOTFS_ALIGNMENT} - 1; base_size -= base_size % ${IMAGE_ROOTFS_ALIGNMENT}; print ((base_size > ${IMAGE_ROOTFS_SIZE} ? base_size : ${IMAGE_ROOTFS_SIZE}) + ${IMAGE_ROOTFS_EXTRA_SPACE}) }'`
+	#  - tested against IMAGE_ROOTFS_SIZE
+	#  - round up ROOTFS_SIZE to IMAGE_ROOTFS_ALIGNMENT
+	ROOTFS_SIZE=`du -ks ${IMAGE_ROOTFS} | awk '{base_size = $1 * ${IMAGE_OVERHEAD_FACTOR}; base_size = ((base_size > ${IMAGE_ROOTFS_SIZE} ? base_size : ${IMAGE_ROOTFS_SIZE}) + ${IMAGE_ROOTFS_EXTRA_SPACE}); if (base_size != int(base_size)) base_size = int(base_size + 1); base_size = base_size + ${IMAGE_ROOTFS_ALIGNMENT} - 1; base_size -= base_size % ${IMAGE_ROOTFS_ALIGNMENT}; print base_size }'`
 	${cmd}
 	# Now create the needed compressed versions
 	cd ${DEPLOY_DIR_IMAGE}/