diff --git a/files/installer.sh b/files/installer.sh
index 547d4bfd58eac0dcd5857a2b7ef3871904c457bb..4f29451874fae239b131fb3823e4c89ab2405024 100755
--- a/files/installer.sh
+++ b/files/installer.sh
@@ -19,7 +19,7 @@ export DISK_DEVICES
 # return:
 #  size in byte
 convertSizeToByte() {
-  local unit=$(echo $1 | sed "s/[1-9\.]*//g")
+  local unit=$(echo $1 | sed "s/[0-9\.]*//g")
   local value=$(echo $1 | sed "s/[a-zA-Z%]*//g")
   local factor=1