Washington D.C. [USA], July 10 (ANI): American singer Jessica Simpson who will be ringing in her 40th birthday on Friday (local time), commemorated the milestone by trying on some vintage jeans from her twenties.

According to People Magazine, the 39-year-old songstress posted on Instagram sharing a mirror selfie of herself rocking the denim, which she paired with a black and purple sweatshirt.

"I have kept these throwback True Religion jeans in my closet for 14 yrs (I'm not exaggerating!)," Simpson captioned the post.

"I figured that since I'm in the final hours of my 30's, I'd give them another try, and hello 40, so nice to meet you," the mother of three added.

Last month, the singer and actress said "YEE-HAW" to the "final days" of her 30s by donning a cowhide-print bikini and embellished black hat as she posed for a photo on the beach.

The 'Irresistible' songstress celebrated another major milestone this week - her wedding anniversary with husband Eric Johnson.

The couple completed six years together on Sunday night with Simpson sharing a sweet tribute to the former NFL player on Instagram, saying that she married her "perfect soulmate."Simpson wrote, "Eric Johnson, my Husband, I love you. 6yrs ago today I married my perfect soulmate. Our unity was written in God's sky of colliding stars. Together we manifest dreams, nurture desire and hold space. Destined, it always has been and always will be, forevermore."She added that a crystal butterfly from Johnson was her "dream gift."The songstress concluded the post with a quote from Emily Bronte's 'Wuthering Heights:' "Whatever our souls are made of, his and mine are the same."Simpson and Johnson share three children, 8-year-old Maxwell Drew, 7-year-old Ace Knute, and 15 months old Birdie Mae. (ANI)