diff --git a/s/update-revision b/s/update-revision
index 0b6e3f6ed0..8f1250f5dc 100755
--- a/s/update-revision
+++ b/s/update-revision
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 if [ -d ../../.git ]; then
   git describe --always --exclude='*' --abbrev=40 --dirty
   echo 'git'