I agree with Ron; you're doing it wrong.
It's true that, if you have QA specialists in your Scrum Team, they can't test a specific feature on day 1 of your sprint; but I bet there's a load of other stuff they can be doing, like working out how to "blackbox" test it, working with the developer who's implementing the feature to gain understanding in how to test it (and see what unit tests the developer is writing so as to remove duplication). Or working on a different feature.
Maybe you need to think differently about breaking down stories, so your QA specialists have things to do early in the sprint that can add business value (I bet there are missing tests that need writing),
Note I've not called them "testers", because you're all one, self-organising team, right?
They should be "T" shaped people (look it up) and might want to have a go at coding, or helping software engineers to think like testers by pair programming.
If your testers are doing lots of manual testing, consider whether you need to encourage them to automate these tasks, so they can do deeper testing that cannot be easily automated.
In a team I worked in, it took us a long time (~6 months IIRC) to align Dev and QA into a single sprint. It's hard, but it is possible. We had QA running one sprint behind for a while, but that wasn't good enough.
I think you've got a topic for your next retrospective: ask the team how they think it should be improved.