Castle star Nathan Fillion recently sat down to address rumors of a possible breakup between the show's two lead characters.

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Fillion, who plays Castle on the series, attended Comic-Con this weekend where he spoke with TVLine about the ABC series. Amid news that new show runners Alexi Hawley and Terence Paul Winter would be "shaking things up" in season 8, fans have been worried about what this means for the show.

TVLine asked Fillion directly about the possibility of Castle and Beckett (Stana Katic) splitting up, and fans it looks like fans shouldn't give up hope.

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"Don't be worried," he answered.

Discussing the idea of shaking things up a bit in season 8, Fillion felt that it's a necessary part of moving a show forward.

"In order for a show to continue and to move forward, things have to change," he explained. "And things have changed, every year, for these two. It's simply just another change and it's going to continue to be great. It's all part of keeping it moving forward and not boring anybody with exactly what happened last season."

Fillion was also asked if season 8 might be the last season of Castle but Fillion did not know. "Hard to say," he admitted, without giving a concrete answer either way.

Watch the entire interview below.

Castle season 8 is set to premiere Monday, Sept. 21 at 8 p.m. ET/PT on ABC.

Tags: Castle television ABC