diff --git a/RtAudio.cpp b/RtAudio.cpp
index 5d493663..61b4708e 100644
--- a/RtAudio.cpp
+++ b/RtAudio.cpp
@@ -5287,6 +5287,8 @@ void RtApiWasapi::wasapiThread()
 // Various revisions for RtAudio 4.0 by Gary Scavone, April 2007
 // Changed device query structure for RtAudio 4.0.7, January 2010
 
+#include <mmsystem.h>
+#include <mmreg.h>
 #include <dsound.h>
 #include <assert.h>
 #include <algorithm>