To disable synchronization context you should call the [ConfigureAwait](<https://msdn.microsoft.com/en-us/library/system.threading.tasks.task.configureawait(v=vs.110).aspx>)
method:
async Task() Foo()
{
await Task.Run(() => Console.WriteLine("Test"));
}
. . .
Foo().ConfigureAwait(false);
ConfigureAwait provides a means to avoid the default SynchronizationContext capturing behavior; passing false for the flowContext parameter prevents the SynchronizationContext from being used to resume execution after the await.
Quote from It’s All About the SynchronizationContext.