diff --git a/scripts/gen_manpage.sh b/scripts/gen_manpage.sh
index aed24fc..0ce6110 100755
--- a/scripts/gen_manpage.sh
+++ b/scripts/gen_manpage.sh
@@ -38,6 +38,6 @@ cat "$5" \
  | sed -E 's/	ttrts -/	ttrts \\-/g'   		>> $TEMP
 
 
-if [ ! -e $FILE ] || [ ! -z $( diff $FILE $TEMP ) ]; then
+if [ ! -e $FILE ] || [ ! -z "$( diff $FILE $TEMP )" ]; then
 	mv -f $TEMP $FILE
 fi
diff --git a/scripts/gen_version_header.sh b/scripts/gen_version_header.sh
index 69db452..aec60e2 100755
--- a/scripts/gen_version_header.sh
+++ b/scripts/gen_version_header.sh
@@ -13,6 +13,6 @@ HEADER="// Auto generated ttrts version header
 echo "$HEADER" > "version.h.tmp"
 
 # If no difference
-if [ ! -e version.h ] || [ ! -z $( diff version.h version.h.tmp ) ]; then
+if [ ! -e version.h ] || [ ! -z "$( diff version.h version.h.tmp )" ]; then
 	mv -f version.h.tmp version.h
 fi