diff --git a/BizHawk.Client.EmuHawk/CustomControls/HexTextBox.cs b/BizHawk.Client.EmuHawk/CustomControls/HexTextBox.cs
index 083990e49b..5db3b08369 100644
--- a/BizHawk.Client.EmuHawk/CustomControls/HexTextBox.cs
+++ b/BizHawk.Client.EmuHawk/CustomControls/HexTextBox.cs
@@ -137,6 +137,26 @@ namespace BizHawk.Client.EmuHawk
 		{
 			Text = val.HasValue ? string.Format(_addressFormatStr, val) : string.Empty;
 		}
+
+		public void SetFromLong(long val)
+		{
+			Text = string.Format(_addressFormatStr, val);
+		}
+
+		public long? ToLong()
+		{
+			if (string.IsNullOrWhiteSpace(Text))
+			{
+				if (Nullable)
+				{
+					return null;
+				}
+
+				return 0;
+			}
+
+			return long.Parse(Text, NumberStyles.HexNumber);
+		}
 	}
 
 	public class UnsignedIntegerBox : TextBox, INumberBox
diff --git a/BizHawk.Client.EmuHawk/tools/Watch/WatchEditor.cs b/BizHawk.Client.EmuHawk/tools/Watch/WatchEditor.cs
index fcb94c8779..ac3b7292e9 100644
--- a/BizHawk.Client.EmuHawk/tools/Watch/WatchEditor.cs
+++ b/BizHawk.Client.EmuHawk/tools/Watch/WatchEditor.cs
@@ -84,7 +84,7 @@ namespace BizHawk.Client.EmuHawk
 					else
 					{
 						NotesBox.Text = _watchList[0].Notes;
-						AddressBox.SetFromRawInt((int)(_watchList[0].Address ?? 0)); // int to long todo
+						AddressBox.SetFromLong(_watchList[0].Address ?? 0);
 					}
 
 					SetBigEndianCheckBox();
@@ -213,7 +213,7 @@ namespace BizHawk.Client.EmuHawk
 				default:
 				case Mode.New:
 					var domain = MemoryDomains.FirstOrDefault(d => d.Name == DomainDropDown.SelectedItem.ToString());
-					var address = AddressBox.ToRawInt() ?? 0;
+					var address = AddressBox.ToLong() ?? 0;
 					var notes = NotesBox.Text;
 					var type = Watch.StringToDisplayType(DisplayTypeDropDown.SelectedItem.ToString());
 					var bigendian = BigEndianCheckBox.Checked;