diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MapperPropAttribute.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MapperPropAttribute.cs
index 5e834c4ede..b5d86f6bc4 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MapperPropAttribute.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MapperPropAttribute.cs
@@ -1,4 +1,6 @@
+using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 
 namespace BizHawk.Emulation.Cores.Nintendo.NES
 {
@@ -11,51 +13,35 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 	{
 		public static void Populate(INesBoard board, NES.NESSyncSettings settings)
 		{
-			var fields = board.GetType().GetFields();
-			foreach (var field in fields)
+			foreach (var fi in board.MapperProps())
 			{
-				var attrib = field.GetCustomAttributes(typeof(MapperPropAttribute), false).OfType<MapperPropAttribute>().SingleOrDefault();
-				if (attrib == null)
-				{
-					continue;
-				}
-
-				string name = field.Name;
+				var name = fi.Name;
 				if (!settings.BoardProperties.ContainsKey(name))
 				{
-					settings.BoardProperties.Add(name, (string)Convert.ChangeType(field.GetValue(board), typeof(string)));
+					settings.BoardProperties.Add(name, (string) Convert.ChangeType(fi.GetValue(board), typeof(string)));
 				}
 			}
 		}
 
 		public static void Apply(INesBoard board)
 		{
-			var fields = board.GetType().GetFields();
-			foreach (var field in fields)
+			foreach (var fi in board.MapperProps())
 			{
-				var attribs = field.GetCustomAttributes(false);
-				foreach (var attrib in attribs)
+				if (!board.InitialRegisterValues.TryGetValue(fi.Name, out var value)) continue;
+				try
 				{
-					if (attrib is MapperPropAttribute)
-					{
-						string name = field.Name;
-
-						if (board.InitialRegisterValues.TryGetValue(name, out var value))
-						{
-							try
-							{
-								field.SetValue(board, Convert.ChangeType(value, field.FieldType));
-							}
-							catch (Exception e) when (e is InvalidCastException || e is FormatException || e is OverflowException)
-							{
-								throw new InvalidOperationException("Auto Mapper Properties were in a bad format!", e);
-							}
-						}
-
-						break;
-					}
+					fi.SetValue(board, Convert.ChangeType(value, fi.FieldType));
+				}
+				catch (Exception e) when (e is InvalidCastException || e is FormatException || e is OverflowException)
+				{
+					throw new InvalidOperationException("Auto Mapper Properties were in a bad format!", e);
 				}
 			}
 		}
+
+		/// <remarks>actually fields</remarks>
+		public static IEnumerable<FieldInfo> MapperProps(this INesBoard board)
+			=> board.GetType().GetFields()
+				.Where(static fi => fi.GetCustomAttribute<MapperPropAttribute>(inherit: false) is not null);
 	}
 }
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs
index eef17e7d3b..8b09de9a36 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs
@@ -102,22 +102,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		}
 
 		public bool HasMapperProperties
-		{
-			get
-			{
-				var fields = Board.GetType().GetFields();
-				foreach (var field in fields)
-				{
-					var attrib = field.GetCustomAttributes(typeof(MapperPropAttribute), false).OfType<MapperPropAttribute>().SingleOrDefault();
-					if (attrib != null)
-					{
-						return true;
-					}
-				}
-
-				return false;
-			}
-		}
+			=> Board.MapperProps().Any();
 
 		public bool IsVS => _isVS;