diff --git a/Source/OpenTK/Platform/Windows/WMInput.cs b/Source/OpenTK/Platform/Windows/WMInput.cs
index 1f6df515..53ba800b 100644
--- a/Source/OpenTK/Platform/Windows/WMInput.cs
+++ b/Source/OpenTK/Platform/Windows/WMInput.cs
@@ -80,7 +80,7 @@ namespace OpenTK.Platform.Windows
                     return;
 
                 case WindowMessage.MOUSEWHEEL:
-                    mouse.Wheel += (int)(msg.WParam.ToInt32() >> 16) / 120;
+                    mouse.Wheel += (msg.WParam.ToInt32() >> 16) / 120;
                     return;
 
                 case WindowMessage.LBUTTONDOWN: