diff --git a/stepmania/src/arch/Sound/RageSoundDriver_WDMKS.cpp b/stepmania/src/arch/Sound/RageSoundDriver_WDMKS.cpp
index a061f28181..9d2ea6c247 100644
--- a/stepmania/src/arch/Sound/RageSoundDriver_WDMKS.cpp
+++ b/stepmania/src/arch/Sound/RageSoundDriver_WDMKS.cpp
@@ -21,6 +21,17 @@
 
 typedef KSDDKAPI DWORD WINAPI KSCREATEPIN(HANDLE, PKSPIN_CONNECT, ACCESS_MASK, PHANDLE);
 
+#ifndef KSAUDIO_SPEAKER_5POINT1_SURROUND
+#define KSAUDIO_SPEAKER_5POINT1_SURROUND
+	(SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY | SPEAKER_SIDE_LEFT  | SPEAKER_SIDE_RIGHT)
+#endif
+
+#ifndef KSAUDIO_SPEAKER_7POINT1_SURROUND
+#define KSAUDIO_SPEAKER_7POINT1_SURROUND \
+	(SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY | \
+	 SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT | SPEAKER_SIDE_LEFT | SPEAKER_SIDE_RIGHT)
+#endif
+
 struct WinWdmFilter;
 
 struct WinWdmPin
@@ -648,7 +659,7 @@ static void FillWFEXT( WAVEFORMATEXTENSIBLE* pwfext, DeviceSampleFormat sampleFo
 	case 1: pwfext->dwChannelMask = KSAUDIO_SPEAKER_MONO; break;
 	case 2: pwfext->dwChannelMask = KSAUDIO_SPEAKER_STEREO; break;
 	case 4: pwfext->dwChannelMask = KSAUDIO_SPEAKER_QUAD; break;
-	case 6: pwfext->dwChannelMask = KSAUDIO_SPEAKER_5POINT1_SURROUND; break; // or KSAUDIO_SPEAKER_5POINT1
+	case 6: pwfext->dwChannelMask = KSAUDIO_SPEAKER_5POINT1; break; // or KSAUDIO_SPEAKER_5POINT1_SURROUND
 	case 8: pwfext->dwChannelMask = KSAUDIO_SPEAKER_7POINT1_SURROUND; break; // or KSAUDIO_SPEAKER_7POINT1
 	}