Locking configurations to certain repositories

Consider the following snippet

repositories {
  ivy {
    name 'ForFooStuff'
    url 'http://foo.com/repo'

configurations {

dependencies {
  foo 'foo:bar:1.0'

If I knew that dependencies for configuration foo is only available on the foo.com Ivy repository, is there any way to tell Gradle to only use that repo for when resolving dependencies for foo?

At the moment this is not possible in gradle

Thanks René. It is something that could be useful, but I can work around it for now.