diff --git a/libexec/nuageinit/nuageinit b/libexec/nuageinit/nuageinit
--- a/libexec/nuageinit/nuageinit
+++ b/libexec/nuageinit/nuageinit
@@ -397,7 +397,13 @@
 		nuage.upgrade_packages()
 	end
 else
-	local res, err = os.execute(path .. "/" .. ud)
+	local res, err
+	if line and line:match("^#!/bin/sh") then
+		res, err = os.execute("sh " .. path .. "/" .. ud)
+	else
+		res, err = os.execute(path .. "/" .. ud)
+	end
+
 	if not res then
 		nuage.err("error executing user-data script: " .. err)
 	end