diff --git a/BizHawk.Client.Common/tools/Watch/ByteWatch.cs b/BizHawk.Client.Common/tools/Watch/ByteWatch.cs
index f5ecd6204b..24bd2f79f8 100644
--- a/BizHawk.Client.Common/tools/Watch/ByteWatch.cs
+++ b/BizHawk.Client.Common/tools/Watch/ByteWatch.cs
@@ -232,7 +232,7 @@ namespace BizHawk.Client.Common
 			get
 			{
 				string diff = string.Empty;
-				byte diffVal = Convert.ToByte(_value - _previous);
+				int diffVal = _value - _previous;
 				if (diffVal > 0)
 				{
 					diff = "+";
@@ -242,7 +242,7 @@ namespace BizHawk.Client.Common
 					diff = "-";
 				}
 
-				return string.Format("{0}{1}", diff, FormatValue(diffVal));
+				return string.Format("{0}{1}", diff, FormatValue((byte)Math.Abs(diffVal)));
 			}
 		}
 
diff --git a/BizHawk.Client.Common/tools/Watch/WordWatch.cs b/BizHawk.Client.Common/tools/Watch/WordWatch.cs
index b8e1268ce3..8d8e06f8f9 100644
--- a/BizHawk.Client.Common/tools/Watch/WordWatch.cs
+++ b/BizHawk.Client.Common/tools/Watch/WordWatch.cs
@@ -245,7 +245,18 @@ namespace BizHawk.Client.Common
 		{
 			get
 			{
-				return FormatValue((ushort)(_previous - _value));
+				string diff = string.Empty;
+				int diffVal = _value - _previous;
+				if (diffVal > 0)
+				{
+					diff = "+";
+				}
+				else if (diffVal < 0)
+				{
+					diff = "-";
+				}
+
+				return string.Format("{0}{1}", diff, FormatValue((ushort)Math.Abs(diffVal)));
 			}
 		}