Nintendo Switch Joy-Con drift is a major hassle, especially for those who prefer to play their Switch in undocked mode. Now, a new study from the UK consumer group Which? reports that it’s found evidence that the Joy-Con drft is due to a fundamental design flaw.

According to the group, the plastic circuit boards within the Joy-Con controllers show wear around the stick slider contact points, even only after months of use. Additionally, dust and other grit can easily enter the mechanism, further exacerbating the problem. The group has called on Nintendo to replace or repair all affected Joy-Cons in the UK as part of a compensation plan.

In response, Nintendo issued a statement claiming that the number of Joy-Cons that develop drift is “small,” and that the company has continued to improve the controllers in the years since the Switch’s release in 2017. While the number of impacted Joy-Cons is unclear, a report from Which? found that two in five controllers tested had drift. However, it’s worth noting that Nintendo usually replaces Joy-Cons with drift free of charge if you contact Nintendo Support. Back in 2021, a YouTuber claimed to find a fix for the problem, but sending your Joy-Cons to Nintendo is probably the safer choice overall.