Using the right Licence

I don’t want to use any software I shouldn’t, or offend copyright owners by not publishing the right licence.
I originally released the app with the
GPL-3+ licence
The application now has a dependency on OpenCV, which has the
Apache 2.0 licence
I don’t suppose I can have two licences. Should I just switch to Apache? I’m no expert on licensing matters, What consequences might switching to Apache have?

Apache 2.0 is compatible with GPLv3 Apache License v2.0 and GPL Compatibility You can include Apache 2.0 software in GPLv3 software. So no changes should be required.

Thanks for a quick and clear answer, backed up with a reputable link.