diff --git a/pdcurses/pad.c b/pdcurses/pad.c
index 253e1c40..b741d21d 100644
--- a/pdcurses/pad.c
+++ b/pdcurses/pad.c
@@ -193,9 +193,9 @@ int pnoutrefresh(WINDOW *w, int py, int px, int sy1, int sx1, int sy2, int sx2)
     if (sx1 < 0)
         sx1 = 0;
 
-    if (!w || !(w->_flags & (_PAD|_SUBPAD)) || 
+    if ((!w || !(w->_flags & (_PAD|_SUBPAD)) || 
         (sy2 >= LINES) || (sx2 >= COLS)) ||
-        (sy2 < sy1) || (sx2 < sx1)
+        (sy2 < sy1) || (sx2 < sx1))
         return ERR;
 
     sline = sy1;