diff --git a/include/ntapi/nt_blitter.h b/include/ntapi/nt_blitter.h
index 529a843..2546412 100644
--- a/include/ntapi/nt_blitter.h
+++ b/include/ntapi/nt_blitter.h
@@ -27,7 +27,7 @@ typedef struct _nt_blitter_params {
 	uint32_t	srvtid;			__optional
 	uint32_t	flags;			__optional
 	int32_t		lock_tries;		__optional
-	int32_t		round_trips;		__optional
+	uint32_t	round_trips;		__optional
 	void *		hsignal_blt;		__optional
 	void *		hsignal_app;		__optional
 	void *		bitmap;			__optional