Droopy headliner...how'd you fix it?

Searched the site, but very little info...so, I'll ask "how did you fix your droopy around the edges headliner?"
My 07 SR5 headliner is starting to sag/ let go where it meets the top of the windshield...both sides/seats. It will stick back if I just use my hand/finger to smooth it flat, but only stays for awhile.
What product and/or method is best for re-sticking it, short of removing the entire liner? Thanks in advance...

 

It is the fabric layer or the whole headliner? The headliner is held in by clips.

 

Just the fabric, didn't know the liner is clipped in.

 

A local upholstery shop may have some adhesive that will work.

 

Gonna try some fabric adhesive that I got at Wallyworld on Friday...big can of 3M spray contact cement was $20 almost. Yikes! Hope I don't glue my fingers to the headliner!

 

Post how it goes, mine has begun the same fate and was thinking of using some spray adhesive too

 

Couldn't figure out how I'd use the 3M spray without schmuttzing out my windshield. Mine is sagging drivers/passengers side where headliner meets top of the windshield.

 

Okay, 1 tube of this from Stuffmart = $6. Took an old business card off my workshop bench, put a bead of this along the short edge of the card and wiped on the headliner edge by the windshield, on both drivers & passenger sides, then used my finger to roll/seat the fabric up/onto the headliner...nice and flat. Stuck well, now to see if it lasts & doesn't sag. Truck is parked, windows up on the driveway in morning sun...should heat up & dry quickly.
I'll post results in a few days.

 

Okay, two days later and no fabric droop...it stuck to the FabriTac & stayed put. Dried glue in that area feels like rough airplane glue for models when I was a kid. Seems a good $6 solution so far.

 

Result!...no sagging, easy fix.

 

I did the 3M headliner adhesive in the back, doesn't leave any type of hard points or obvious parts. I have the same issue up front, I'll use cardboard and tape for this.