diff --git a/BizHawk.Client.Common/lua/EmuLuaLibrary.Events.cs b/BizHawk.Client.Common/lua/EmuLuaLibrary.Events.cs
index 2520830dc1..073724d987 100644
--- a/BizHawk.Client.Common/lua/EmuLuaLibrary.Events.cs
+++ b/BizHawk.Client.Common/lua/EmuLuaLibrary.Events.cs
@@ -185,7 +185,7 @@ namespace BizHawk.Client.Common
 
 		[LuaMethodExample("local steveonm = event.onmemoryexecute(\r\n\tfunction()\r\n\t\tconsole.log( \"Fires after the given address is executed by the core. If no address is given, it will attach to every memory read\" );\r\n\tend\r\n\t, 0x200, \"Frame name\", \"System Bus\" );")]
 		[LuaMethod("onmemoryexecute", "Fires after the given address is executed by the core. If no address is given, it will attach to every memory read")]
-		public string OnMemoryExecute(LuaFunction luaf, uint address = null, string name = null, string domain = null)
+		public string OnMemoryExecute(LuaFunction luaf, uint? address = null, string name = null, string domain = null)
 		{
 			try
 			{