Credible Nintendo insider source, Emily Rogers, has reported that the next big Zelda may miss its March 2017 launch window.

Originally slated for 2015, Breath of the Wild has been delayed to 2016 and then March 2017 to become a hot launch title for Nintendo next big home console, Switch. However due to the projects ambition and scale it seems the game will be further delayed to ensure localization and bug testing is completed. The new expected launch window will be Summer of 2017.

More sources have now come forward and corroborated my information. They’ve told me that localization for Breath of the Wild might not be finished until the end of December. After localization is completed, this game will require between (at least) four-to-six months of testing. As I mentioned earlier, this is one of Nintendo’s largest and most ambitious games ever. The amount of testing required for a huge open-world game like this is enormous. Nintendo’s intention is to have the game as bug free as possible.

While it’s still considered a rumor I wouldn’t be shocked. This is the first open world game Nintendo has ever developed so bug testing and quality checking will take longer than expected. Hopefully things work out between now and March but don’t be surprised if Nintendo announces a delay.

UPDATE: EuroGamer has also confirmed the delay from its own sources.