diff --git a/plugins/nginx-vhosts/functions b/plugins/nginx-vhosts/functions
index 49270ae9e55..5d8d61510d7 100755
--- a/plugins/nginx-vhosts/functions
+++ b/plugins/nginx-vhosts/functions
@@ -145,7 +145,7 @@ nginx_build_config() {
     if [[ -z "$DOKKU_APP_LISTEN_PORT" ]] && [[ -z "$DOKKU_APP_LISTEN_IP" ]]; then
       shopt -s nullglob
       for DOKKU_APP_IP_FILE in $DOKKU_ROOT/$APP/IP.web.*; do
-        DOKKU_APP_PORT_FILE=$(echo $DOKKU_APP_IP_FILE | sed -e "s:IP:PORT:g")
+        DOKKU_APP_PORT_FILE="${DOKKU_APP_IP_FILE//IP/PORT}"
         DOKKU_APP_LISTENER_IP=$(< $DOKKU_APP_IP_FILE)
         DOKKU_APP_LISTENER_PORT=$(< $DOKKU_APP_PORT_FILE)
 
diff --git a/tests.mk b/tests.mk
index 67a50562481..03858db02e8 100644
--- a/tests.mk
+++ b/tests.mk
@@ -61,10 +61,9 @@ lint:
 	# these are disabled due to their expansive existence in the codebase. we should clean it up though
 	# SC2034: VAR appears unused - https://github.com/koalaman/shellcheck/wiki/SC2034
 	# SC2086: Double quote to prevent globbing and word splitting - https://github.com/koalaman/shellcheck/wiki/SC2086
-	# SC2001: See if you can use ${variable//search/replace} instead. - https://github.com/koalaman/shellcheck/wiki/SC2001
 	@echo linting...
 	@$(QUIET) shellcheck ./contrib/dokku_client.sh
-	@$(QUIET) find . -not -path '*/\.*' | xargs file | egrep "shell|bash" | egrep -v "directory|toml" | awk '{ print $$1 }' | sed 's/://g' | grep -v dokku_client.sh | xargs shellcheck -e SC2034,SC2086,SC2001
+	@$(QUIET) find . -not -path '*/\.*' | xargs file | egrep "shell|bash" | egrep -v "directory|toml" | awk '{ print $$1 }' | sed 's/://g' | grep -v dokku_client.sh | xargs shellcheck -e SC2034,SC2086
 
 unit-tests:
 	@echo running unit tests...