How to change a script bundle's icon?

I don’t seem to find an answer to this question in the forum: is it possible to change the icon of a script bundle (not an application!) by using an icon in the Resources folder? Script bundles have an Info.plist file, so I thought that dragging an icon into the Resources folder and adding a CFBundleIconFile key in the plist would do the trick (as it does for applications). But it doesn’t seem to work: the script bundle still has the same generic icon. Am I missing something or the only way to change a script bundle’s icon is to paste it into the Finder’s Info panel (or to modify the script bundle’s metadata in some other way)?

A script bundle is a document, and as such, its icon is set by its app.