Sen. Rand Paul (R-KY) is the latest GOP presidential candidate to jump on 2016 frontrunner Ben Carson’s theory that the pyramids were created by the biblical figure Joseph to store grain.

“I’’m really big into conspiracy theories, so I think they were probably built by the aliens as grain silos, don’t you think,” Paul joked, when asked about Carson’s idea on 1110AM WBT, as reported by Buzzfeed.

Carson has defended the idea that the pyramids were built for grain storage — not as pharaohs’ tombs, as modern archaeology holds — since Buzzfeed recently unearthed a video of the neurosurgeon making a 1998 commencement address referencing the theory. Donald Trump — Carson’s main rival — has said he plans to use the idea against Carson.

On the radio show, Paul was also asked about a tweet Trump retweeted and then deleted that suggested former Gov. Jeb Bush (R-FL) was a Nazi.

“I think when you started out with maybe whether the aliens had built the pyramids, you had me, but then when you got to Nazism, I think you’ve just gone too far,” Paul said.