diff --git a/os400/config400.default b/os400/config400.default
index 35e3283e..5147cb20 100644
--- a/os400/config400.default
+++ b/os400/config400.default
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Copyright (C) The libssh2 project and its contributors.
 # SPDX-License-Identifier: BSD-3-Clause
 
diff --git a/os400/initscript.sh b/os400/initscript.sh
index 78889aed..bbe78c07 100755
--- a/os400/initscript.sh
+++ b/os400/initscript.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Copyright (C) The libssh2 project and its contributors.
 # SPDX-License-Identifier: BSD-3-Clause
 
@@ -94,6 +94,7 @@ action_needed()
 {
         [ ! -e "${1}" ] && return 0
         [ -n "${2}" ] || return 1
+        # shellcheck disable=SC3013
         [ "${1}" -ot "${2}" ] && return 0
         return 1
 }
@@ -121,8 +122,7 @@ canonicalize_path()
         do      IFS="${IFSSAVE}"
                 case "${C}" in
                 .)      ;;
-                ..)     R=$(expr \
-                                 "${R}" : '^\(.*/\)..*')
+                ..)     R="$(expr "${R}" : '^\(.*/\)..*')"
                         ;;
                 ?*)     R="${R}${C}/"
                         ;;
@@ -147,8 +147,7 @@ make_module()
         MODULES="${MODULES} ${1}"
         MODIFSNAME="${LIBIFSNAME}/${1}.MODULE"
         action_needed "${MODIFSNAME}" "${2}" || return 0;
-        SRCDIR="$(dirname \
-                          "$(canonicalize_path "${2}")")"
+        SRCDIR="$(dirname "$(canonicalize_path "${2}")")"
 
         #       #pragma convert has to be in the source file itself, i.e.
         #               putting it in an include file makes it only active
diff --git a/os400/make-include.sh b/os400/make-include.sh
index 2de6d6d7..5fa911af 100755
--- a/os400/make-include.sh
+++ b/os400/make-include.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Copyright (C) The libssh2 project and its contributors.
 # SPDX-License-Identifier: BSD-3-Clause
 #
diff --git a/os400/make-rpg.sh b/os400/make-rpg.sh
index 7a6f3cd1..68b50009 100755
--- a/os400/make-rpg.sh
+++ b/os400/make-rpg.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Copyright (C) The libssh2 project and its contributors.
 # SPDX-License-Identifier: BSD-3-Clause
 #
diff --git a/os400/make-src.sh b/os400/make-src.sh
index 408d0122..4c399da8 100755
--- a/os400/make-src.sh
+++ b/os400/make-src.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Copyright (C) The libssh2 project and its contributors.
 # SPDX-License-Identifier: BSD-3-Clause
 #
diff --git a/os400/make.sh b/os400/make.sh
index 2e40755e..84640db7 100755
--- a/os400/make.sh
+++ b/os400/make.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Copyright (C) The libssh2 project and its contributors.
 # SPDX-License-Identifier: BSD-3-Clause
 #