diff --git a/src/sna/sna_dri.c b/src/sna/sna_dri.c
index 4dc96473..69c1b425 100644
--- a/src/sna/sna_dri.c
+++ b/src/sna/sna_dri.c
@@ -1091,15 +1091,15 @@ can_exchange(struct sna * sna,
 	WindowPtr win = (WindowPtr)draw;
 	PixmapPtr pixmap;
 
-	if (draw->type == DRAWABLE_PIXMAP)
-		return true;
-
 	if (front->format != back->format) {
 		DBG(("%s: no, format mismatch, front = %d, back = %d\n",
 		     __FUNCTION__, front->format, back->format));
 		return false;
 	}
 
+	if (draw->type == DRAWABLE_PIXMAP)
+		return true;
+
 	pixmap = get_window_pixmap(win);
 	if (pixmap == sna->front) {
 		DBG(("%s: no, window is attached to the front buffer\n",