diff --git a/src/sna/sna.h b/src/sna/sna.h
index 8cfa98a9..a5141811 100644
--- a/src/sna/sna.h
+++ b/src/sna/sna.h
@@ -463,6 +463,11 @@ extern xf86CrtcPtr sna_covering_crtc(struct sna *sna,
 extern bool sna_wait_for_scanline(struct sna *sna, PixmapPtr pixmap,
 				  xf86CrtcPtr crtc, const BoxRec *clip);
 
+static inline uint64_t ust64(int tv_sec, int tv_usec)
+{
+	return (uint64_t)tv_sec * 1000000 + tv_usec;
+}
+
 #if HAVE_DRI2_H
 bool sna_dri2_open(struct sna *sna, ScreenPtr pScreen);
 void sna_dri2_page_flip_handler(struct sna *sna, struct drm_event_vblank *event);
diff --git a/src/sna/sna_dri2.c b/src/sna/sna_dri2.c
index 6991c91a..d86c86e7 100644
--- a/src/sna/sna_dri2.c
+++ b/src/sna/sna_dri2.c
@@ -2402,8 +2402,8 @@ fail:
 		if (pipe < 0)
 			pipe = 0;
 		*msc = sna->dri2.last_swap[pipe].msc;
-		*ust = ((uint64_t)sna->dri2.last_swap[pipe].tv_sec * 100000 +
-			sna->dri2.last_swap[pipe].tv_usec);
+		*ust = ust64(sna->dri2.last_swap[pipe].tv_sec,
+			     sna->dri2.last_swap[pipe].tv_usec);
 		return TRUE;
 	}
 
@@ -2420,7 +2420,7 @@ fail:
 		sna->dri2.last_swap[pipe].tv_usec = vbl.reply.tval_usec;
 		sna->dri2.last_swap[pipe].msc = vbl.reply.sequence;
 
-		*ust = ((CARD64)vbl.reply.tval_sec * 1000000) + vbl.reply.tval_usec;
+		*ust = ust64(vbl.reply.tval_sec, vbl.reply.tval_usec);
 		*msc = vbl.reply.sequence;
 		DBG(("%s: msc=%llu, ust=%llu\n", __FUNCTION__,
 		     (long long)*msc, (long long)*ust));