diff --git a/SConstruct b/SConstruct
index 328e71df2..2d2d83d51 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1353,12 +1353,16 @@ static void terminate_handler()
 			# inputs.
 			user_settings.max_axes_per_joystick = user_settings.max_buttons_per_joystick = user_settings.max_hats_per_joystick = 0
 		successflags['CPPDEFINES'] = CPPDEFINES = successflags.get('CPPDEFINES', [])[:]
+		# use Redbook if at least one of the following applies
+		#    1. we are on SDL1
+		#    2. we are building for a platform for which we have a custom CD implementation (currently only win32)
+		use_redbook = int(not sdl2 or user_settings.host_platform == 'win32')
 		CPPDEFINES.extend((
 			('DXX_MAX_JOYSTICKS', user_settings.max_joysticks),
 			('DXX_MAX_AXES_PER_JOYSTICK', user_settings.max_axes_per_joystick),
 			('DXX_MAX_BUTTONS_PER_JOYSTICK', user_settings.max_buttons_per_joystick),
 			('DXX_MAX_HATS_PER_JOYSTICK', user_settings.max_hats_per_joystick),
-			('DXX_USE_SDL_REDBOOK_AUDIO', int(not sdl2 or sys.platform in ['win32', 'msys'])), # there is a win32 rbaudio now
+			('DXX_USE_SDL_REDBOOK_AUDIO', use_redbook),
 		))
 		context.Display('%s: checking whether to enable joystick support...%s\n' % (self.msgprefix, 'yes' if user_settings.max_joysticks else 'no'))
 		# SDL2 removed CD-rom support.
diff --git a/common/arch/win32/rbaudio.cpp b/common/arch/win32/rbaudio.cpp
index b3d0fb816..40939f388 100644
--- a/common/arch/win32/rbaudio.cpp
+++ b/common/arch/win32/rbaudio.cpp
@@ -93,6 +93,7 @@ static unsigned mci_GetTrackOffset(const int track)
 		Warning("RBAudio win32/MCI: cannot determine track %i offset (%lx)", track, mciError);
 		return -1;
 	}
+	// dwReturn is a 32-bit value in MSF format, so DWORD_PTR > DWORD is not a problem
 	return mci_TotalFramesMsf(mciStatusParms.dwReturn);
 }
 
@@ -108,6 +109,7 @@ static unsigned mci_GetTrackLength(const int track)
 		Warning("RBAudio win32/MCI: cannot determine track %i length (%lx)", track, mciError);
 		return -1;
 	}
+	// dwReturn is a 32-bit value in MSF format, so DWORD_PTR > DWORD is not a problem
 	return mci_TotalFramesMsf(mciStatusParms.dwReturn);
 }
 
@@ -367,12 +369,13 @@ void RBACheckFinishedHook()
 		// and allow a bit of a leeway when checking if so.
 
 		DWORD checkValue = playEnd;
+		// dwReturn is a 32-bit value in MSF format, so DWORD_PTR > DWORD is not a problem
 		DWORD thisFrames = mci_TotalFramesMsf(mciStatusParms.dwReturn);
 
 		if (thisFrames == lastFrames)
 			checkValue = checkValue < 64 ? 0 : checkValue - 64; // prevent underflow
 
-		if (redbook_finished_hook && playEnd > 0 && lastFrames >= checkValue)
+		if (redbook_finished_hook && playEnd > 0 && thisFrames >= checkValue)
 		{
 			con_puts(CON_VERBOSE, "RBAudio win32/MCI: Playback done, calling finished-hook");
 			redbook_finished_hook();