Gabrielle Union's key to a lasting marriage is not taking her husband ''for granted''.

The 45-year-old actress recently celebrated four years of marriage to her husband Dwayne Wade, and has said the secret to making their relationship last is making sure they express how much they mean to one another, and ''staying rooted in their love''.

Speaking to People magazine, Gabrielle said: ''We have to make sure, especially when we have these long distance relationships, that we don't take each other for granted. And making sure that communication is not just on point - We know where the kids are, we know the dogs have been picked up, that our mother has got birthday gifts or whatever it is - but just reminding ourselves and staying rooted in our love and our friendship, and making sure we express that, which we try to every day.''

The 'Breaking In' star doesn't have children of her own with Dwayne but is stepmother to his brood, Zaire, 16, Zion, 11, and Xavier, four, and the basketball star recently praised her for being there for him and his kids.

He wrote on Instagram: ''She's a star in her most important role. I wanna acknowledge my wife and the kids step mom for being everything that each boy and i have needed her to be. We couldn't have wished for more @gabunion ... Thank you for loving us! (sic)''

Gabrielle had previously opened up about suffering ''eight or nine'' miscarriages and says she has spent three years as a ''prisoner of trying to get pregnant'' through fertility treatment.

In an excerpt from her new book, 'We're Going to Need More Wine', she revealed: ''I have had eight or nine miscarriages. For three years, my body has been a prisoner of trying to get pregnant - I've either been about to go into an IVF cycle, in the middle of an IVF cycle, or coming out of an IVF cycle ... [We] remain bursting with love and ready to do anything to meet the child we've both dreamed of.''