VSTS Release Management: Visual Studio Test Task

We have a release definition setup within VSTS with a Visual Studio Test task to run our automated test suite. The problem we're experiencing is that the release is succeeding regardless of whether there are failing tests or not. There doesn't appear to be any control within the task configuration over the behaviour of error handling/test failures.

Does anybody have any workarounds or solutions for what we're trying to achieve?

Thanks.