diff --git a/activate.sh b/activate.sh
index 7ab975a..ff931a0 100755
--- a/activate.sh
+++ b/activate.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Let PATH include 'xpanes' and 'tmux-xpanes'.
 if ! (type xpanes > /dev/null 2>&1 &&
diff --git a/install.sh b/install.sh
index e7aba4e..515883c 100755
--- a/install.sh
+++ b/install.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -ue
 
 readonly THIS_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
diff --git a/man/create.sh b/man/create.sh
index 3117203..b2117dc 100755
--- a/man/create.sh
+++ b/man/create.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # In bash,
 # Use md2man (https://github.com/sunaku/md2man) to generate man file like this.
diff --git a/test/unit.sh b/test/unit.sh
index 10c32ac..85b8541 100755
--- a/test/unit.sh
+++ b/test/unit.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Test cases given by this file is not executed on the CI server.
 # This file is just used for brief behavior checking during the development.
diff --git a/test/update_yaml.sh b/test/update_yaml.sh
index cc7c6d2..ee651f5 100644
--- a/test/update_yaml.sh
+++ b/test/update_yaml.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 readonly THIS_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
 
diff --git a/uninstall.sh b/uninstall.sh
index 07f4cf5..ccf2d94 100755
--- a/uninstall.sh
+++ b/uninstall.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -ue
 
 readonly THIS_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"