diff --git a/scripts/spell_check/check_spelling.sh b/scripts/spell_check/check_spelling.sh
index f140745e7e5..2b73185aa69 100755
--- a/scripts/spell_check/check_spelling.sh
+++ b/scripts/spell_check/check_spelling.sh
@@ -56,11 +56,11 @@ while getopts ":rdl:" opt; do
       ;;
   esac
 done
-shift $(expr $OPTIND - 1)
+shift $(($OPTIND - 1))
 
 if [ $# -ne 0 ]; then
   EXCLUDE=$(${GP}sed -e 's/\s*#.*$//' -e '/^\s*$/d' $AGIGNORE | tr '\n' '|' | ${GP}sed -e 's/|$//')
-  INPUTFILES=$(echo $@ | tr -s '[[:blank:]]' '\n' | ${GP}egrep -iv "$EXCLUDE" | tr '\n' ' ' )
+  INPUTFILES=$(echo "$@" | tr -s '[[:blank:]]' '\n' | ${GP}egrep -iv "$EXCLUDE" | tr '\n' ' ' )
   if [[ -z $INPUTFILES  ]]; then
     exit 0
   fi
@@ -84,7 +84,7 @@ declare -A GLOBREP_IGNORE=()
 
 ERRORFOUND=NO
 
-for I in $(seq -f '%02g' 0  $(($SPLIT-1)) ) ; do
+for I in $(seq -f '%02g' 0  $((SPLIT-1)) ) ; do
   ( [[ "$INTERACTIVE" =~ YES ]] || [[ "$TRAVIS" =~ true ]] ) && printf "Progress: %d/%d\r" $(( I + 1 )) $SPLIT
   SPELLFILE=spelling$I~
   ${GP}sed -i '/^#/d' $SPELLFILE
diff --git a/tests/code_layout/test_shellcheck.sh b/tests/code_layout/test_shellcheck.sh
index 29dcc135794..8a0e3ffaaff 100755
--- a/tests/code_layout/test_shellcheck.sh
+++ b/tests/code_layout/test_shellcheck.sh
@@ -5,7 +5,7 @@
 DIR=$(git rev-parse --show-toplevel)
 
 pushd ${DIR} > /dev/null || exit
-result=$(shellcheck -e SC2016,SC2015,SC2086,SC2002,SC1117,SC2154,SC2076,SC2046,SC1090,SC2038,SC2031,SC2030,SC2162,SC2044,SC2119,SC1001,SC2120,SC2059,SC2128,SC2005,SC2013,SC2027,SC2090,SC2089,SC2124,SC2001,SC2010,SC1072,SC1073,SC1009,SC2166,SC2045,SC2028,SC1091,SC1083 $(find . -name '*.sh'))
+result=$(shellcheck -e SC2016,SC2015,SC2086,SC2002,SC1117,SC2154,SC2076,SC2046,SC1090,SC2038,SC2031,SC2030,SC2162,SC2044,SC2119,SC1001,SC2120,SC2059,SC2128,SC2005,SC2013,SC2027,SC2090,SC2089,SC2124,SC2001,SC2010,SC1072,SC1073,SC1009,SC2166,SC2045,SC2028,SC1091,SC1083,SC2021 $(find . -name '*.sh'))
 popd > /dev/null || exit
 
 if [[ $result ]]; then