It's the end of an era for longtime comic book collectors in London.

The Comic Book Collector, which is the oldest shop of its kind in the Forest City, will close its doors for good on Thursday.

"It's just been slowly spiralling down as far as customers," said Tim Morris, who's the store's third and current owner.

Morris, who first set foot in the shop as a customer in 1984 and became its owner in 2001, said recent changes by one of the two biggest comic book companies are largely to blame for his store's diminishing customer base.

Despite its success at the box office, sales of Marvel comic books have declined in recent years, just as the company made significant changes to many of its most popular characters.

"(Fans) see The Avengers or Iron Man (in the films), and they come in and want to read those characters, but they're not in the comics anymore," he said.

"Hulk is not Bruce Banner ... and Captain America's a bad guy."

Owner Tim Morris in front of his store. Much of the shop's merchandise is selling at a deep discount as staff prepare to close its doors for good. (Chris dela Torre)

According to Morris, Marvel's slumping sales have come at a cost to his store.

"That $1000 a month (covered) my rent here at the shop," says Morris. "And it's not there anymore."

The Comic Book Collector's final day of business is Thursday, Aug. 31.

Most of its merchandise is already selling at a deep discount.