diff --git a/RtAudio.cpp b/RtAudio.cpp
index defb800..e0713a0 100644
--- a/RtAudio.cpp
+++ b/RtAudio.cpp
@@ -4941,7 +4941,7 @@ void RtApiWasapi::wasapiThread()
   // declare local stream variables
   RtAudioCallback callback = ( RtAudioCallback ) stream_.callbackInfo.callback;
   BYTE* streamBuffer = NULL;
-  unsigned long captureFlags = 0;
+  DWORD captureFlags = 0;
   unsigned int bufferFrameCount = 0;
   unsigned int numFramesPadding = 0;
   unsigned int convBufferSize = 0;