F# Query Expression "The field, constructor or member 'Contains' is not defined"

I'm trying to get this example from the Query Expressions page to work. I've got the database setup and I've made many small bits of code work. ``` let idQuery = query { for id in [1; 2; 5; 10] do select id } query { for student in db.Student do where (idQuery.Contains(student.StudentID)) select student } ``` But all I get is the error: The field, constructor or member 'Contains' is not defined What am I missing? I've got other examples to work.