Import RSQLite in R package

Question

I am trying to add RSQLite package to Imports instead of Depends in my package. In DESCRIPTION I have:

Imports:
    sqldf,
    RPostgreSQL,
    RSQLite

In NAMESPACE there is:

import(RPostgreSQL)
import(RSQLite)
import(sqldf)

But then when I load my package it fails:

> library(devtools)
> load_all()
Loading mondrianr
Loading required namespace: sqldf
Loading required namespace: tcltk
Loading required namespace: RPostgreSQL
> check()
...
check_table_exists: no visible global function definition for
  'dbDriver'
prepare_infrastructure: no visible global function definition for
  'dbDriver'

This will result in failed examples, because dbDriver is method exported by RSQLite, but RSQLite namespace is not loaded. I've tried to add @importMethodsFrom RSQLite dbDriver, but the result is the same.

What should I try next?