diff --git a/scripts/deploy-ebook-to-www b/scripts/deploy-ebook-to-www
index fa9f6d24..28a015fb 100755
--- a/scripts/deploy-ebook-to-www
+++ b/scripts/deploy-ebook-to-www
@@ -12,7 +12,7 @@ EOF
 	exit
 }
 die(){ printf "\033[0;7;31mError:\033[0m %s\n" "${1}" 1>&2; exit 1; }
-require(){ command -v "$1" > /dev/null 2>&1 || { suggestion=""; if [ ! -z "$2" ]; then suggestion=" $2"; fi; die "$1 is not installed.${suggestion}"; } }
+require(){ command -v "$1" > /dev/null 2>&1 || { suggestion=""; if [ -n "$2" ]; then suggestion=" $2"; fi; die "$1 is not installed.${suggestion}"; } }
 if [ $#  -eq 1 ]; then if [ "$1" = "--help" ] || [ "$1" = "-h" ]; then usage; fi fi
 # End boilerplate