diff --git a/projects/rubocop.org/rubocop b/projects/rubocop.org/rubocop
index cf667d0d9e..17575c0b52 100644
--- a/projects/rubocop.org/rubocop
+++ b/projects/rubocop.org/rubocop
@@ -1,3 +1,5 @@
+#!/bin/sh
+
 export GEM_HOME="$(cd "$(dirname "$0")"/.. && pwd)"
 export GEM_PATH="$GEM_HOME"
 export PATH="$GEM_HOME/gems/bin:$PATH"