diff --git a/po/check_translations.sh b/po/check_translations.sh
index 76562cb..146b810 100755
--- a/po/check_translations.sh
+++ b/po/check_translations.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 # Go to po directory
 cd "$(dirname "${0}")" || exit 1
diff --git a/tests/test_duplicate_mime_types.sh b/tests/test_duplicate_mime_types.sh
index e7dfb15..1b1245b 100755
--- a/tests/test_duplicate_mime_types.sh
+++ b/tests/test_duplicate_mime_types.sh
@@ -1,20 +1,20 @@
-#!/usr/bin/env bash
-set -euo pipefail
+#!/bin/sh
+set -eu
 
 : ${1:?filename argument missing}
 xml_db_file="${1}"
-test -f ${xml_db_file} || {
-    printf "%s: no such file\n" ${xml_db_file} >&2
+test -f "${xml_db_file}" || {
+    printf '%s: no such file\n' "${xml_db_file}" >&2
     exit 1
 }
 
 duplicated=$(
     xmllint --xpath \
             "//*[local-name()='mime-type' or local-name()='alias']/@type" \
-            ${xml_db_file} | tr ' ' '\n' | sort | uniq -d
+            "${xml_db_file}" | tr ' ' '\n' | sort | uniq -d
 )
 
-if [[ -n "${duplicated}" ]]; then
+if [ -n "${duplicated}" ]; then
     echo "*************************************************************"
     echo "** Some mime-types are duplicated, fix before committing:  **"
     echo "${duplicated}"
diff --git a/tests/test_generic_icons.sh b/tests/test_generic_icons.sh
index de6c56f..41877f6 100755
--- a/tests/test_generic_icons.sh
+++ b/tests/test_generic_icons.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 xml_db_file="${1}"
 
diff --git a/tests/test_mime.sh b/tests/test_mime.sh
index 49c531b..b3e9fef 100755
--- a/tests/test_mime.sh
+++ b/tests/test_mime.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 set -e
 
 source_root="${1}"
diff --git a/tests/test_staging.sh b/tests/test_staging.sh
index a993dce..b62878c 100755
--- a/tests/test_staging.sh
+++ b/tests/test_staging.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 set -e
 
 source_root="${1}"