Although Apple provides relatively frequent software updates to iPhone users, one particular bug has persisted over the years. Many online reports indicate that iPhone alarms sound at the wrong times, even when running the latest iOS 18 update.

According to a new post on Reddit, iPhone users have been suffering from a critical bug that causes their alarms to be delayed — sometimes by hours. According to comments, the issue still exists on the latest version of iOS 18.2.1, which Apple released to the public earlier this week. Similar complaints have been filed over the past few years, suggesting the bug is at least five years old.

Given that millions of people rely on their iPhone alarm clocks to wake up for work or school every day, the impact of a vulnerability could be catastrophic. For example, one reviewer mentioned missing a key exam and deciding to opt for a physical clock to avoid it happening again in the future. Likewise, other Reddit users missed scheduled tasks in the built-in Reminders app, suggesting the issue isn’t limited to Apple Clock.

Although a few Android Authority Employees who actively use iPhones have yet to encounter this error, and numerous online reports suggest it’s fairly common. Currently, there appears to be no known workaround to ensure that your iPhone alarm doesn’t go off at the wrong time. If you’re worried it might affect you, consider a dedicated clock or Android phone as an alternative.

We’ve reached out to Apple for comment and will update this article if we hear back.