diff --git a/Makefile b/Makefile
index 6de731bd6..1f5aed156 100644
--- a/Makefile
+++ b/Makefile
@@ -401,6 +401,7 @@ lint:
 	flake8 --config=scripts/flake8.cfg test/inhfd/*.py
 	flake8 --config=scripts/flake8.cfg test/others/rpc/config_file.py
 	flake8 --config=scripts/flake8.cfg lib/py/images/pb2dict.py
+	shellcheck --version
 	shellcheck scripts/*.sh
 	shellcheck scripts/ci/*.sh scripts/ci/apt-install
 	shellcheck test/others/crit/*.sh
diff --git a/scripts/ci/apt-install b/scripts/ci/apt-install
index 0b5a6fe3f..5a790901a 100755
--- a/scripts/ci/apt-install
+++ b/scripts/ci/apt-install
@@ -12,7 +12,7 @@ max_apt_retries=5
 # hashsum mismatches, DNS errors and similar things
 while true; do
 	(( install_retry_counter+=1 ))
-	if [ ${install_retry_counter} -gt ${max_apt_retries} ]; then
+	if [ "${install_retry_counter}" -gt "${max_apt_retries}" ]; then
 		exit 1
 	fi
 	# shellcheck disable=SC2068
@@ -20,5 +20,5 @@ while true; do
 
 	# In case it is a network error let's wait a bit.
 	echo "Retrying attempt ${install_retry_counter}"
-	sleep ${install_retry_counter}
+	sleep "${install_retry_counter}"
 done
diff --git a/scripts/systemd-autofs-restart.sh b/scripts/systemd-autofs-restart.sh
index 65481b551..4d2be1c10 100755
--- a/scripts/systemd-autofs-restart.sh
+++ b/scripts/systemd-autofs-restart.sh
@@ -45,8 +45,8 @@ bindmount=""
 
 function remove_bindmount {
 	if [ -n "$bindmount" ]; then
-		$JOIN_CT umount $bindmount
-		$JOIN_CT rm -rf $bindmount
+		$JOIN_CT umount "$bindmount"
+		$JOIN_CT rm -rf "$bindmount"
 		bindmount=""
 	fi
 }
@@ -107,7 +107,7 @@ function save_mountpoint {
 	# Nothing to do, if no file system is on top of autofs
 	[ "$top_mount_fs_type" = "autofs" ] && return
 
-	bindmount=$($JOIN_CT mktemp -d)
+	bindmount="$($JOIN_CT mktemp -d)"
 	if [ -z "$bindmount" ]; then
 		echo "Failed to create temporary directory"
 		return 1
diff --git a/scripts/tmp-files.sh b/scripts/tmp-files.sh
index 33be4dafa..78edd9a9e 100755
--- a/scripts/tmp-files.sh
+++ b/scripts/tmp-files.sh
@@ -26,7 +26,7 @@ IMGFILE=$CRTOOLS_IMAGE_DIR"/tmpfiles.tar.gz"
 MY_NAME=$(basename "$0")
 
 case "$CRTOOLS_SCRIPT_ACTION" in
-	$POSTDUMP )
+	"$POSTDUMP")
 		if [ "$#" -lt 1 ]; then
 			echo "$MY_NAME: ERROR! No files are given."
 			exit 1
@@ -34,7 +34,7 @@ case "$CRTOOLS_SCRIPT_ACTION" in
 		tar "$DUMPARGS" "$IMGFILE" -- "$@"
 		exit $?
 		;;
-	$PRERESTORE )
+	"$PRERESTORE")
 		if [ "$#" -ne 0 ]; then
 			echo "$MY_NAME: ERROR! Not expected script args."
 			exit 1