diff --git a/rpi23-gen-image.sh b/rpi23-gen-image.sh
index 9cde19c..aa90260 100755
--- a/rpi23-gen-image.sh
+++ b/rpi23-gen-image.sh
@@ -224,7 +224,7 @@ ENABLE_CRYPTFS=${ENABLE_CRYPTFS:=false}
 CRYPTFS_PASSWORD=${CRYPTFS_PASSWORD:=""}
 CRYPTFS_MAPPING=${CRYPTFS_MAPPING:="secure"}
 CRYPTFS_CIPHER=${CRYPTFS_CIPHER:="aes-xts-plain64"}
-CRYPTFS_HASH=${CRYPTFS_HASH:=":sha512"}
+CRYPTFS_HASH=${CRYPTFS_HASH:="sha512"}
 CRYPTFS_XTSKEYSIZE=${CRYPTFS_XTSKEYSIZE:=512}
 #Dropbear-initramfs supports unlocking encrypted filesystem via SSH on bootup
 CRYPTFS_DROPBEAR=${CRYPTFS_DROPBEAR:=false}