diff --git a/BizHawk.Client.EmuHawk/tools/Lua/LuaTextBox.cs b/BizHawk.Client.EmuHawk/tools/Lua/LuaTextBox.cs
index 1423ad0147..535fa0ca38 100644
--- a/BizHawk.Client.EmuHawk/tools/Lua/LuaTextBox.cs
+++ b/BizHawk.Client.EmuHawk/tools/Lua/LuaTextBox.cs
@@ -1,5 +1,8 @@
-using System.Windows.Forms;
+using System;
+using System.Globalization;
+using System.Windows.Forms;
 
+using BizHawk.Common;
 using BizHawk.Client.Common;
 
 namespace BizHawk.Client.EmuHawk
@@ -28,6 +31,109 @@ namespace BizHawk.Client.EmuHawk
 			base.OnKeyPress(e);
 		}
 
+		protected override void OnKeyDown(KeyEventArgs e)
+		{
+			
+			if (e.KeyCode == Keys.Up)
+			{
+				switch (_boxType)
+				{
+					default:
+					case BoxType.All:
+						base.OnKeyDown(e);
+						break;
+					case BoxType.Hex:
+					case BoxType.Signed:
+					case BoxType.Unsigned:
+						Increment();
+						break;
+				}
+			}
+			else if (e.KeyCode == Keys.Down)
+			{
+				switch (_boxType)
+				{
+					default:
+					case BoxType.All:
+						base.OnKeyDown(e);
+						break;
+					case BoxType.Hex:
+					case BoxType.Signed:
+					case BoxType.Unsigned:
+						Decrement();
+						break;
+				}
+			}
+			else
+			{
+				base.OnKeyDown(e);
+			}
+		}
+
+		private void Increment()
+		{
+			string text = String.IsNullOrWhiteSpace(Text) ? "0" : Text;
+			switch (_boxType)
+			{
+				case BoxType.Hex:
+					var hval = uint.Parse(text, NumberStyles.HexNumber);
+					if (hval < uint.MaxValue)
+					{
+						hval++;
+						Text = hval.ToString("X");
+					}
+					break;
+				case BoxType.Signed:
+					var sval = int.Parse(text);
+					if (sval < int.MaxValue)
+					{
+						sval++;
+						Text = sval.ToString();
+					}
+					break;
+				case BoxType.Unsigned:
+					var uval = uint.Parse(text);
+					if (uval < uint.MaxValue)
+					{
+						uval++;
+						Text = uval.ToString();
+					}
+					break;
+			}
+		}
+
+		private void Decrement()
+		{
+			string text = String.IsNullOrWhiteSpace(Text) ? "0" : Text;
+			switch (_boxType)
+			{
+				case BoxType.Hex:
+					var hval = uint.Parse(text, NumberStyles.HexNumber);
+					if (hval < uint.MaxValue)
+					{
+						hval--;
+						Text = hval.ToString("X");
+					}
+					break;
+				case BoxType.Signed:
+					var sval = int.Parse(text);
+					if (sval < int.MaxValue)
+					{
+						sval--;
+						Text = sval.ToString();
+					}
+					break;
+				case BoxType.Unsigned:
+					var uval = uint.Parse(text);
+					if (uval < uint.MaxValue)
+					{
+						uval--;
+						Text = uval.ToString();
+					}
+					break;
+			}
+		}
+
 		private void SpecificValueBox_KeyPress(object sender, KeyPressEventArgs e)
 		{
 			if (e.KeyChar == '\b') return;