Index: resources/data/validator/geometry.mapcss
===================================================================
--- resources/data/validator/geometry.mapcss	(revision 17423)
+++ resources/data/validator/geometry.mapcss	(working copy)
@@ -352,7 +352,8 @@
 }
 
 /* #12646, #12992, #16334 */
-way[waterway=~/^(stream|river|drain)$/]!:closed >[index=-1] node[natural!=sinkhole][natural!=cave_entrance]!:connection:in-downloaded-area { 
+way[waterway=~/^(stream|river|drain)$/]!:closed >[index=-1] node[natural!=sinkhole][natural!=cave_entrance]!:connection:in-downloaded-area, 
+way[waterway=~/^(stream|river|drain)$/]!:closed >[index=-1] node[natural!=sinkhole][natural!=cave_entrance].new { 
   throwWarning: tr("Waterway ends without a connection to another waterway or the direction of the waterway is wrong.");
 }