diff --git a/src/option.c b/src/option.c
index 941ea66..cd50e8d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -9493,10 +9493,10 @@
 	    errmsg = e_positive;
 	    curwin->w_p_nuw = 1;
 	}
-	if (curwin->w_p_nuw > 10)
+	if (curwin->w_p_nuw > 20)
 	{
 	    errmsg = e_invarg;
-	    curwin->w_p_nuw = 10;
+	    curwin->w_p_nuw = 20;
 	}
 	curwin->w_nrwidth_line_count = 0; /* trigger a redraw */
     }