diff --git a/simpleaudio.d b/simpleaudio.d
index ace1cbd..43f6b23 100644
--- a/simpleaudio.d
+++ b/simpleaudio.d
@@ -640,7 +640,7 @@ struct AudioOutput {
 				// since this is wave out, it promises not to write...
 				auto buffer = buffers[i][];
 				header.lpData = cast(void*) buffer.ptr;
-				header.dwBufferLength = buffer.length * short.sizeof;
+				header.dwBufferLength = cast(int) buffer.length * cast(int) short.sizeof;
 				header.dwFlags = WHDR_BEGINLOOP | WHDR_ENDLOOP;
 				header.dwLoops = 1;