Reports of bike theft are a common site on Seattle’s crime map.

Three bicycles were reported stolen between 8:15 a.m. on Sept. 26 and 8:15 a.m. on Sept. 27. That might not seem like much, but those are just the reported thefts that have already been recorded in the system.

The Seattle Police Department received 1,561 bike theft reports in 2015. That’s almost double the number in 2010, The Seattle Times reports. And, according to the Times, the number doesn’t include bikes stolen during burglaries, which are a separate crime category. In contrast, police returned 183 bikes, according to the Times.

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So it’s not surprising that people are taking matters into their own hands. Bike Index, for example, has become a popular step in fighting bike theft. The service allows victims to register a stolen bike, getting the information out to the public and making it tougher for a thief to steal.

Some people are taking the fight against bike theft a step further.

Daniel Idzkowski, the founder of Skunklock, created a bicycle lock that releases a noxious smell when it is cut into.

“We were thinking of exploding locks,” Idzkowski told Seattle’s Morning News. “That wouldn’t fly.”

So they went with a lock that makes people vomit.

The chemicals used in the Skunklock are all food grade, according to Idzkowski. The core chemical, for example, can be found in food such as butter and cheese. So far, the creators of Skunklock have only tested it on themselves. Under those circumstances, Idzkowski says it has been “extremely effective.”

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Of course, someone who really wants to steal a bike locked with a Skunklock could do so, but then they would have to use a mask.

“That’s the idea,” Idzkowski said. “We’re not calling ourselves a complete solution, but a deterrent.”

Idzkowski says if a bike thief has to wear a “Breaking Bad-type” suit and a gas mask, he’s sure the invention is making a difference.