Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/UnclosedWays.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/UnclosedWays.java	(revision 8576)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/UnclosedWays.java	(revision 8577)
@@ -137,5 +137,5 @@
     private final UnclosedWaysCheck[] checks = {
         new UnclosedWaysCheck(1101, "natural",   marktr("natural type {0}"),
-                new HashSet<>(Arrays.asList("coastline", "cliff", "tree_row", "ridge", "arete", "gorge"))),
+                new HashSet<>(Arrays.asList("coastline", "cliff", "tree_row", "ridge", "valley", "arete", "gorge"))),
         new UnclosedWaysCheck(1102, "landuse",   marktr("landuse type {0}")),
         new UnclosedWaysCheck(1103, "amenities", marktr("amenities type {0}")),