Index: trunk/data/validator/deprecated.mapcss
===================================================================
--- trunk/data/validator/deprecated.mapcss	(revision 8135)
+++ trunk/data/validator/deprecated.mapcss	(revision 8137)
@@ -405,2 +405,9 @@
   suggestAlternative: "natural=valley";
 }
+
+/* see #10346 */
+way[oneway=1] {
+  throwWarning: tr("{0} is deprecated", "{0.tag}");
+  suggestAlternative: "oneway=yes";
+  fixAdd: "oneway=yes";
+}