diff --git a/hack/format.sh b/hack/format.sh
index e1c389e..89575f8 100755
--- a/hack/format.sh
+++ b/hack/format.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 set -e
 
 cd "$(dirname "${0}")/.." || exit 1