diff --git a/gen.sh b/gen.sh
index 62b96e1..621816f 100755
--- a/gen.sh
+++ b/gen.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Periph Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
@@ -6,10 +6,6 @@
 set -eu
 cd "$(dirname $0)"
 
-# Determine the docker image to use.
-TAG="$(cat ./tag)"
-IMAGE="marcaruel/hugo-tidy:${TAG}"
-
 echo "Tips:"
 echo " - Use --buildDrafts to render drafts."
 
@@ -17,6 +13,10 @@ echo " - Use --buildDrafts to render drafts."
 # expected.
 if [ $# == 0 ]; then
   if (which docker > /dev/null); then
+    # Determine the docker image to use.
+    TAG="$(cat ./tag)"
+    IMAGE="marcaruel/hugo-tidy:${TAG}"
+
     echo "Using hugo-tidy"
     # See https://github.com/maruel/hugo-tidy/ for more info.
     # First, pull the image only if missing.
diff --git a/new_post.sh b/new_post.sh
index bf119f6..4107983 100755
--- a/new_post.sh
+++ b/new_post.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2020 The Periph Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
diff --git a/serve.sh b/serve.sh
index 48e90bd..1598657 100755
--- a/serve.sh
+++ b/serve.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Periph Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
@@ -6,16 +6,16 @@
 set -eu
 cd "$(dirname $0)"
 
-# Determine the docker image to use.
-TAG="$(cat ./tag)"
-IMAGE="marcaruel/hugo-tidy:${TAG}"
-
 echo "Tips:"
 echo " - Use --bind=0.0.0.0 to be accessible on the local network."
 echo " - Use --buildDrafts to render drafts."
 
 if (which docker > /dev/null); then
   echo "Using hugo-tidy"
+  # Determine the docker image to use.
+  TAG="$(cat ./tag)"
+  IMAGE="marcaruel/hugo-tidy:${TAG}"
+
   # See https://github.com/maruel/hugo-tidy/ for more info.
   # First, pull the image only if missing.
   [ ! -z $(docker images -q "${IMAGE}") ] || docker pull "${IMAGE}"