diff --git a/tools/GSDumpGUI/Library/GSDXWrapper.cs b/tools/GSDumpGUI/Library/GSDXWrapper.cs
index fc0c9df476..eaaca9cce8 100644
--- a/tools/GSDumpGUI/Library/GSDXWrapper.cs
+++ b/tools/GSDumpGUI/Library/GSDXWrapper.cs
@@ -215,7 +215,7 @@ namespace GSDumpGUI
 
                 GSsetGameCRC(dump.CRC, 0);
 
-                NativeMethods.SetClassLong(hWnd,/*GCL_HICON*/ -14, Program.hMainIcon.ToInt32());
+                NativeMethods.SetClassLong(hWnd,/*GCL_HICON*/ -14, (uint)Program.hMainIcon.ToInt32());
 
                 fixed (byte* freeze = dump.StateData)
                 {
diff --git a/tools/GSDumpGUI/Library/NativeMethods.cs b/tools/GSDumpGUI/Library/NativeMethods.cs
index 947310b14d..7715e581c3 100644
--- a/tools/GSDumpGUI/Library/NativeMethods.cs
+++ b/tools/GSDumpGUI/Library/NativeMethods.cs
@@ -62,7 +62,7 @@ namespace GSDumpGUI
 
         [SuppressUnmanagedCodeSecurityAttribute]
         [DllImport("user32", CharSet = CharSet.Ansi)]
-        public extern static int SetClassLong(IntPtr HWND, int index, long newlong);
+        public extern static int SetClassLong(IntPtr HWND, int index, uint newlong);
 
         [SuppressUnmanagedCodeSecurityAttribute]
         [DllImport("user32", CharSet = CharSet.Ansi)]