diff --git a/include/dsound.h b/include/dsound.h
index 06799011de5975d9bff52515df60dcb2a9a10238..5c14b56111c7a00e54ba9d7341cecd6a0b12f96b 100644
--- a/include/dsound.h
+++ b/include/dsound.h
@@ -110,6 +110,7 @@ DEFINE_GUID(DSDEVID_WinePlayback,        0x40316A1D,0x605B,0xD611,0x87,0xC6,0x00
 
 #define DS_OK				0
 #define DS_NO_VIRTUALIZATION            MAKE_HRESULT(0, _FACDS, 10)
+#define DS_INCOMPLETE                   MAKE_HRESULT(0, _FACDS, 20)
 #define DSERR_ALLOCATED			MAKE_DSHRESULT(10)
 #define DSERR_CONTROLUNAVAIL		MAKE_DSHRESULT(30)
 #define DSERR_INVALIDPARAM		E_INVALIDARG