diff --git a/bin/common_defs.sh b/bin/common_defs.sh
index 2757b7a27..7e048482f 100644
--- a/bin/common_defs.sh
+++ b/bin/common_defs.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 DEBUG="${DEBUG:-0}"
 if [ "$DEBUG" -eq 1 ]; then
diff --git a/bin/common_defs2.sh b/bin/common_defs2.sh
index f1991b37d..fe81665aa 100644
--- a/bin/common_defs2.sh
+++ b/bin/common_defs2.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ## NOTE: those are defined separately from `common_defs.sh` because
 ## they require `common_functions.sh` to be sourced prior to sourcing
diff --git a/bin/common_functions.sh b/bin/common_functions.sh
index 3ec099f49..8279ca5d3 100644
--- a/bin/common_functions.sh
+++ b/bin/common_functions.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Echo to stderr on errors
 echoerr() { echo "ERROR: $*" 1>&2; }