Demi Lovato has a new tattoo in tribute to her late friend.

The 'Sorry Not Sorry' singer spoke of her devastation earlier this month after her pal Thomas passed away following a struggle with addiction and now she's got a permanent reminder of her buddy.

Demi took to Instagram to show off the inking of a letter T on her forearm, which is situated just above the rose design she got four years ago.

She captioned the post: ''A T for Tommy. RIP you special angel. Love you forever. Thank you for the ink @rafael_valdez.. it's beautiful and I'm so grateful for this.(sic)''

The 27-year-old star paid tribute to her friend last week following his death.

She wrote on her Instagram Story: ''Please hold your loved ones tight. Tell them they are special and that you love them. Make sure they know it. RIP to my boo @sirtruss.

''Addiction is NO joke.. heaven gained this beautiful angel last night because of that terrible disease. I'm crushed and will always miss you @sirtruss. (sic)''

Following Thomas' death, Demi - who has previously battled addiction issues herself - called for people to ''ask for help'' if they or someone they know is ''struggling''.

She added: ''If you or someone you know is struggling please know it's okay to ask for help. (sic)''

Demi suffered a near-fatal overdose in July last year, and spent time in a treatment centre for addiction.

A month later, the 'Skyscraper' hitmaker broke her silence for the first time since she was admitted, and thanked her fans for their ''positive thoughts and prayers''.

She wrote: ''I have always been transparent about my journey with addiction. What I've learned is that this illness is not something that disappears or fades with time. It is something I must continue to overcome and have not done yet. I want to thank God for keeping me alive and well. To my fans, I am forever grateful for all of your love and support throughout this past week and beyond. Your positive thoughts and prayers have helped me navigate through this difficult time. I now need time to heal and focus on my sobriety and road to recovery. The love you have all shown will never be forgotten and I look forward to the day where I can say I came out on the other side. I will keep fighting. (sic)''