When Infinity Ward and Activision first revealed the multiplayer for Call of Duty: Modern Warfare, they put a lot of emphasis on a realistic approach. While past entries in the COD franchise have tried to offer a fast-paced experience bolstered by futuristic tech and wall running, Modern Warfare keeps things as grounded as it can. However, there is one detail that doesn’t seem to reflect the real world.

While playing the multiplayer in Call of Duty: Modern Warfare many players noticed that they couldn’t see through the smoke from a grenade while using a Thermal Scope. At first, most players just assumed that this was a bug and chalked it up to launch week issues for Modern Warfare – like the Xbox One crashes – but it appears that is not the case.

One Call of Duty player who goes by DKarma on Twitter, reached out to Infinity Ward multiplayer designer David Mickner to ask about the smoke. As it turns out, the inability to see through smoke with Thermal sights is an intentional design choice by IW and not a bug. Mickner explained that it was part of a move towards a more realistic approach.

As one might expect, the Modern Warfare fan base was confused by the response. One of the main reasons to use thermal sights is to be able to counter smoke grenades in a more competitive environment, and without that advantage, smokes are even more useful. Obviously, some players will use the scope just to try to pick out enemies from amidst a background, but others favored Thermals because it eliminated the use of smokes.

The other confusing element is that Infinity Ward explained that this is part of Call of Duty going for a realistic approach. Unless the smoke grenades are the exact same temperature as the human within there would still be some gradient to the heat signatures seen on a thermal scope.

At this point, it’s unlikely that any complaints from fans are going to get Infinity Ward to change the design in Call of Duty: Modern Warfare. The smoke works the way the developer intended and there is no going back now. But the good news for those who like a little more tactical approach to their multiplayer is that night vision multiplayer maps add a fun twist to the franchise formula.

Call of Duty: Modern Warfare is available now for PC, PS4, and Xbox One.