positional operator element mismatch when using both $slice and $ projections

You insert a document with two array fields: db.test.insert( { "importing" : [ { "foo": "a" }, { "foo": "b" } ], "jobs" : [ { "status" : "completed" } ] } ) You try to query it, where you use $slice on one, and $ on another. The query should match the second element in importing, which does not exist in jobs: db.test.find( { "importing.foo": "b" }, { jobs: { '$slice': -1 }, 'importing.$': 1 }) You get: error: { "$err" : "positional operator element mismatch", "code" : 16353 }