During the 1850s, a tailor named Jacob Davis came up with a design detail that revolutionized the apparel industry. By reinforcing blue jeans with metal rivets at their most vulnerable points, he invented a pair of trousers miners could depend on through years of washing and wearing. Jacob would later partner with his cloth supplier Levi Strauss to bring the idea mainstream.

But there’s one place you won’t find the rivets that stud most blue jeans: the crotch. According to this video from TED-Ed tracing the history of blue jeans, rivets originally had a place at the base of the fly. Strauss and Davis reportedly decided to nix the crotch rivet following complaints from miners who discovered the painful effect it produced when squatting above a campfire sans-underpants. So if your crotch seam is always the first to split open, you have Gold Rush-era miners to blame.