diff --git a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IEmulator.cs b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IEmulator.cs
index e31f7f4700..13164fdd0f 100644
--- a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IEmulator.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IEmulator.cs
@@ -1,4 +1,5 @@
 using BizHawk.Emulation.Common;
+using System;
 
 namespace BizHawk.Emulation.Cores.Atari.Atari2600
 {