Upgraded to 1.5 and local app is pointing to production MLab (mongo 3.4) but still getting MongoError: Unrecognized pipeline stage name: '$graphLookup'

I was under the impression if you upgraded to Meteor 1.4.3+ and had a database that was mongo 3.4-- that meteor would automatically use 3.4

However I’m getting this error message that seems to indicate I’m not using 3.4 (otherwise graphLookup should be recognized rigth?).

Do I need to trigger it somewhere myself like this says:

db.adminCommand( { setFeatureCompatibilityVersion: "3.4" } )