diff --git a/tools/ci_build/github/scripts/install_protobuf.sh b/tools/ci_build/github/scripts/install_protobuf.sh
index 3d5c3de..b912b8e 100644
--- a/tools/ci_build/github/scripts/install_protobuf.sh
+++ b/tools/ci_build/github/scripts/install_protobuf.sh
@@ -1,3 +1,4 @@
+#!/bin/bash
 set -e -x
 
 INSTALL_PREFIX='/usr'