$lookup error: "errmsg" : "exception: Unrecognized pipeline stage name: '$lookup'"

[MG]

I want to join 2 collection:

db.col1.aggregate([

    {

        $lookup:{

            from: "col2",       // other table name

            localField: "sql_id",   // name of users table field

            foreignField: "_id", // name of userinfo table field

            as: "sql_info"         // alias for userinfo table

        }

    },

    {   

        $project:{

            sql_id : 1

        } 

    }

]);

But I get:

: aggregate failed

_getErrorWithCode@src/mongo/shell/utils.js:25:13

doassert@src/mongo/shell/assert.js:13:14

assert.commandWorked@src/mongo/shell/assert.js:287:5

DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1312:5

@(shell):1:1

2017-02-24T13:05:39.416+0100 E QUERY    [thread1] Error: command failed: {

"errmsg" : "exception: Unrecognized pipeline stage name: '$lookup'",

"code" : 16436,

"ok" : 0

} : aggregate failed :

_getErrorWithCode@src/mongo/shell/utils.js:25:13

doassert@src/mongo/shell/assert.js:13:14

assert.commandWorked@src/mongo/shell/assert.js:287:5

DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1312:5

@(shell):1:1

 
col1 document:

{ 

    "_id" : ObjectId("58b00dbc97fce010fd1696b7"), 

    "dt_ins" : ISODate("2017-02-24T00:00:00.000+0000"), 

    "sql_id" : "gw8kr1qj01ht3", 

    "username" : "user", 

    "executions" : "", 

    "total_elapsed_sec" : "", 

}

col2 document:

{ 

    "_id" : "gw8kr1qj01ht3", 

    "sql_text" : "select...."

}

[Rhys Campbell]

What version of MongoDB? $lookup was introduced in 3.2 https://docs.mongodb.com/manual/reference/operator/aggregation/lookup/