The value of type "StorageReference" has no 'put' member

I upgraded to firebase 4.0 memory and now I am getting this error saying storageRef does not have a "put" member. It worked before in the old version of Firebase.

    if let selectedImage = selectedImageFromPicker {
        profilePic.image = selectedImage
        if let uploadData = UIImagePNGRepresentation(selectedImage) {
            let storageRef = Storage.storage().reference().child("profile pictures").child("\(Auth.auth().currentUser?.uid).png")
            storageRef.put/*error here*/(uploadData, metadata: nil, completion: {
                (metadata, error) in
                if error != nil {
                    print(error!)
                    return
                }
                print(metadata!)

                if let profilePictureURL = metadata?.downloadURL()?.absoluteString {

                    let ref = FIRDatabase.database().reference()
                    let usersreference = ref.child("users").child(Auth.auth().currentUser?.uid).child("data")
                    usersreference.updateChildValues(["profile picture": profilePictureURL])
                }
            })
        }
    }