diff --git a/.gitignore b/.gitignore
index b25c15b..538c8c5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
+.DS_Store
 *~
diff --git a/arch_delete_aws4.sh b/arch_delete_aws4.sh
index 689eb01..8facdb7 100755
--- a/arch_delete_aws4.sh
+++ b/arch_delete_aws4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # Copyleft https://git.k8s.astropenguin.net/penguin/s3-arch-utils
 
 # ##
diff --git a/arch_delete_many_aws4.sh b/arch_delete_many_aws4.sh
index 8cd11c9..7fcc447 100755
--- a/arch_delete_many_aws4.sh
+++ b/arch_delete_many_aws4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # Copyleft https://git.k8s.astropenguin.net/penguin/s3-arch-utils
 
 # ##
diff --git a/arch_download_aws4.sh b/arch_download_aws4.sh
index d5d75d7..3b9156e 100755
--- a/arch_download_aws4.sh
+++ b/arch_download_aws4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # Copyleft https://git.k8s.astropenguin.net/penguin/s3-arch-utils
 
 # ##
diff --git a/arch_getacl_aws4.sh b/arch_getacl_aws4.sh
index 3993356..306eade 100755
--- a/arch_getacl_aws4.sh
+++ b/arch_getacl_aws4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # Copyleft https://git.k8s.astropenguin.net/penguin/s3-arch-utils
 
 # ##
diff --git a/arch_list_aws4.sh b/arch_list_aws4.sh
index 3169cd0..6a0d53f 100755
--- a/arch_list_aws4.sh
+++ b/arch_list_aws4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # Copyleft https://git.k8s.astropenguin.net/penguin/s3-arch-utils
 
 # ##
diff --git a/arch_upload_aws4.sh b/arch_upload_aws4.sh
index f7acecb..e122c85 100755
--- a/arch_upload_aws4.sh
+++ b/arch_upload_aws4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # Copyleft https://git.k8s.astropenguin.net/penguin/s3-arch-utils
 
 # ##