diff --git a/stepmania/src/StepMania-net2003.vcproj b/stepmania/src/StepMania-net2003.vcproj
index 7d60895c24..b07e57bf4f 100644
--- a/stepmania/src/StepMania-net2003.vcproj
+++ b/stepmania/src/StepMania-net2003.vcproj
@@ -1927,6 +1927,12 @@ cl /Zl /nologo /c verstub.cpp /Fo"$(IntDir)"\
 			<File
 				RelativePath="RageSoundManager.h">
 			</File>
+			<File
+				RelativePath=".\RageSoundMixBuffer.cpp">
+			</File>
+			<File
+				RelativePath=".\RageSoundMixBuffer.h">
+			</File>
 			<File
 				RelativePath="RageSoundPosMap.cpp">
 			</File>