Table record saving as string when it should be double

Could some explain why Laravel 5 is saving my decimal table record as string?

$table->decimal('bar', 5, 2)->nullable();

Seeder:

[...] // shorten to show what was created
'bar' => 10.5,

Tinker:

App\Foo::find(1)->bar //= "10.5"

I have no issues with integer but issues with double, float

via Chebli Mohamed