diff --git a/source/Debugger/Debug.h b/source/Debugger/Debug.h
index 91ac7d5c..3237e4f6 100644
--- a/source/Debugger/Debug.h
+++ b/source/Debugger/Debug.h
@@ -108,6 +108,18 @@
 //	extern MemorySearchArray_t g_vMemSearchMatches;
 	extern std::vector<int> g_vMemorySearchResults;
 
+// Mouse
+	// NOTE: Keep in sync with MouseButton_t and g_aDebuggerMouseProcessFunc !
+		enum MouseButton_t
+	{
+		 MOUSE_BUTTON_LEFT
+		,MOUSE_BUTTON_MIDDLE
+		,MOUSE_BUTTON_RIGHT
+		,MOUSE_BUTTON_FORWARD
+		,MOUSE_BUTTON_BACKWARD
+		,NUM_MOUSE_BUTTONS
+	};
+
 // Source Level Debugging
 	extern std::string g_aSourceFileName;
 	extern MemoryTextFile_t g_AssemblerSourceBuffer;
diff --git a/source/Frame.cpp b/source/Frame.cpp
index 40fdd55c..feabd036 100644
--- a/source/Frame.cpp
+++ b/source/Frame.cpp
@@ -58,6 +58,20 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include "Configuration/PropertySheet.h"
 #include "Debugger/Debug.h"
 
+// NOTE: These are in <WinUser.h> HOWEVER they are only defined if _WIN32_WINNT > 0x500
+#ifndef WM_XBUTTONDOWN
+	#define WM_XBUTTONDOWN  0x020B
+#endif
+#ifndef WM_XBUTTONUP
+	#define WM_XBUTTONUP    0x020C
+#endif
+#ifndef MK_XBUTTON1
+	#define MK_XBUTTON1     0x0020
+#endif
+#ifndef MK_XBUTTON2
+	#define MK_XBUTTON2     0x0040
+#endif
+
 //#define ENABLE_MENU 0
 #define DEBUG_KEY_MESSAGES 0