Consumer Reports has agreed to give the new MacBook Pro a second look after meeting with Apple and uncovering a software bug that may have caused the inconsistent battery life that led the magazine to withhold its recommendation.

The magazine reported in December that its tests of three different MacBook Pro models produced battery life anywhere from 3.75 hours to 19.6 hours.

On Tuesday, the magazine said that its testing methods turn off a browser’s cache, which apparently triggered a software glitch that could have caused the inconsistent battery life. The magazine said it will retest the laptop’s battery life and report back on its findings.

Apple, for its part, said the bug was an “obscure” one that only occurs if users change the developer settings to turn off Safari’s browser cache.

“This is not a setting used by customers and does not reflect real-world usage,” Apple said in a statement. “Their use of this developer setting also triggered an obscure and intermittent bug reloading icons which created inconsistent results in their lab. After we asked Consumer Reports to run the same test using normal user settings, they told us their MacBook Pro systems consistently delivered the expected battery life.”

Apple said it has also fixed the bug in question in the most recent beta version of Sierra which was released on Monday.

Here’s Apple’s full statement on the issue:

“We appreciate the opportunity to work with Consumer Reports over the holidays to understand their battery test results. We learned that when testing battery life on Mac notebooks, Consumer Reports uses a hidden Safari setting for developing web sites which turns off the browser cache. This is not a setting used by customers and does not reflect real-world usage. Their use of this developer setting also triggered an obscure and intermittent bug reloading icons which created inconsistent results in their lab. After we asked Consumer Reports to run the same test using normal user settings, they told us their MacBook Pro systems consistently delivered the expected battery life. We have also fixed the bug uncovered in this test. This is the best pro notebook we’ve ever made, we respect Consumer Reports and we’re glad they decided to revisit their findings on the MacBook Pro.”

Subscribe to Recode Newsletters Recode Daily (Top News) Events Products Go