Laravel SQLite doesn't deleting in cascade

I am using the SQLite in memory to test my Laravel application. Then i define one table Enterprise this way:

    Schema::create('Enterprise', function(Blueprint $table)
            {
                $table->increments('id');
                $table->string('name');
                $table->integer('address')->unsigned()->index()->nullable();
                $table->foreign('address_id')->references('id')
->on('Address')->onDelete('cascade');
                $table->timestamps();
            });

the address schema:

Schema::create('Address', function(Blueprint $table)
        {
            $table->increments('id');
            $table->timestamps();
        });

But, when i run the test

$emp = Enterprise::find(1)->first();
$emp->delete();
$this->assertEquals(0, Enterprise::all()->count());
$this->assertEquals(0, Address::all()->count());

the test fails in the second assert, it is not deleting in cascade :(

Anyone knows the solution ??