Alyson Hannigan still can't bring herself to watch the 'How I Met Your Mother' spin-off series

The actress told PEOPLE: "I should have [watched]. But I just couldn't.

"It just made me sad because I'm like, oh, that's the same set."

Alyson still has very fond memories of filming the final season of 'How I Met Your Mother'.

The actress - who starred on the hit TV show alongside the likes of Jason Segel, Cobie Smulders and Neil Patrick Harris - said: "I just remember being pretty emotional during it because there were a lot of 'last'. We all took the year to really appreciate all the moments that, we've had so many of, in the however many seasons we did it."

Alyson previously admitted that she had "great memories" of her time on the long-running sitcom.

The actress revealed that she loved working with the show's cast and crew for so many years, and she described 'How I Met Your Mother' as an "incredible show" to be a part of.

Alyson - who also enjoyed huge success with the 'American Pie' film franchise before she joined the sitcom - told PEOPLE: "It's sort of just a montage of great memories.

"That was just such a wonderful job to go to every day and the people were incredible and we just were silly and fun and got to do this incredible show. But it was just a blast. It really was."