Index: trunk/resources/data/validator/geometry.mapcss
===================================================================
--- trunk/resources/data/validator/geometry.mapcss	(revision 16779)
+++ trunk/resources/data/validator/geometry.mapcss	(revision 16783)
@@ -167,6 +167,6 @@
 }
 
-/* Building overlapping building (spatial test) */
-area[building:part][building:part!~/no|entrance/] ⧉ area[building:part][building:part!~/no|entrance/],
+/* Building overlapping building or building:part (spatial test) */
+area[building][building!~/no|entrance/] ⧉ area[building:part][building:part!~/no|entrance/],
 area[building][building!~/no|entrance/] ⧉ area[building][building!~/no|entrance/] {
   throwWarning: tr("Overlapping buildings");