diff --git a/src/Dialog.cpp b/src/Dialog.cpp
index 9a104089..999f8742 100644
--- a/src/Dialog.cpp
+++ b/src/Dialog.cpp
@@ -17,7 +17,7 @@ static const char *version_string =
 	;
 
 // TODO - Inaccurate stack frame
-INT_PTR CALLBACK VersionDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
+DLGPROC_RET CALLBACK VersionDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
 {
 	char string_buffer[104];
 
@@ -58,7 +58,7 @@ INT_PTR CALLBACK VersionDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam
 	return FALSE;
 }
 
-INT_PTR CALLBACK DebugMuteDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
+DLGPROC_RET CALLBACK DebugMuteDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
 {
 	(void)lParam;
 
@@ -102,7 +102,7 @@ INT_PTR CALLBACK DebugMuteDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lPar
 	return FALSE;
 }
 
-INT_PTR CALLBACK DebugSaveDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
+DLGPROC_RET CALLBACK DebugSaveDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
 {
 	char string[100];
 
@@ -135,7 +135,7 @@ INT_PTR CALLBACK DebugSaveDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lPar
 	return FALSE;
 }
 
-INT_PTR CALLBACK QuitDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
+DLGPROC_RET CALLBACK QuitDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
 {
 	switch (Msg)
 	{
diff --git a/src/Dialog.h b/src/Dialog.h
index 628d59e7..1c5b6914 100644
--- a/src/Dialog.h
+++ b/src/Dialog.h
@@ -2,7 +2,7 @@
 
 #include "WindowsWrapper.h"
 
-INT_PTR CALLBACK VersionDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
-INT_PTR CALLBACK DebugMuteDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
-INT_PTR CALLBACK DebugSaveDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
-INT_PTR CALLBACK QuitDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
+DLGPROC_RET CALLBACK VersionDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
+DLGPROC_RET CALLBACK DebugMuteDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
+DLGPROC_RET CALLBACK DebugSaveDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
+DLGPROC_RET CALLBACK QuitDialog(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
diff --git a/src/Main.cpp b/src/Main.cpp
index 806607ed..1d5bcd89 100644
--- a/src/Main.cpp
+++ b/src/Main.cpp
@@ -676,12 +676,12 @@ LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lPar
 			switch (LOWORD(wParam))
 			{
 				case 40001:
-					if (DialogBoxParamA(ghInstance, "DLG_YESNO", hWnd, (DLGPROC)QuitDialog, (LPARAM)"Quit?") == 1)
+					if (DialogBoxParamA(ghInstance, "DLG_YESNO", hWnd, QuitDialog, (LPARAM)"Quit?") == 1)
 						PostMessageA(hWnd, WM_CLOSE, 0, 0);
 					break;
 
 				case 40002:
-					DialogBoxParamA(ghInstance, "DLG_ABOUT", hWnd, (DLGPROC)VersionDialog, 0);
+					DialogBoxParamA(ghInstance, "DLG_ABOUT", hWnd, VersionDialog, 0);
 					break;
 
 				case 40004:
@@ -690,11 +690,11 @@ LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lPar
 					break;
 
 				case 40005:
-					DialogBoxParamA(ghInstance, "DLG_SAVE", hWnd, (DLGPROC)DebugSaveDialog, 0);
+					DialogBoxParamA(ghInstance, "DLG_SAVE", hWnd, DebugSaveDialog, 0);
 					break;
 
 				case 40007:
-					DialogBoxParamA(ghInstance, "DLG_MUTE", hWnd, (DLGPROC)DebugMuteDialog, 0);
+					DialogBoxParamA(ghInstance, "DLG_MUTE", hWnd, DebugMuteDialog, 0);
 					break;
 			}
 
diff --git a/src/WindowsWrapper.h b/src/WindowsWrapper.h
index 22321292..b182e51b 100644
--- a/src/WindowsWrapper.h
+++ b/src/WindowsWrapper.h
@@ -3,7 +3,7 @@
 #include <windows.h>
 
 // Visual Studio 6 is missing these, so define them here
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && _MSC_VER <= 1200
 	#ifndef VK_OEM_PLUS
 	#define VK_OEM_PLUS 0xBB
 	#endif
@@ -23,4 +23,9 @@
 	#ifndef DWORD_PTR
 	#define DWORD_PTR DWORD
 	#endif
+
+	// DLGPROC went from returning BOOL to INT_PTR in later versions, and VC6 doesn't like that
+	#define DLGPROC_RET BOOL
+#else
+	#define DLGPROC_RET INT_PTR
 #endif