diff --git a/lib/Properties.hs b/lib/Properties.hs
index b2d4974c41d8a50e4fccb48a3ca77c1616560f42..51fa567bdd84240f18278a63d9c9d128d3115fcd 100644
--- a/lib/Properties.hs
+++ b/lib/Properties.hs
@@ -197,7 +197,8 @@ checkTileset = do
     checkTilesetProperty :: Property -> LintWriter Tileset
     checkTilesetProperty p@(Property name _value) = case name of
       "tilesetCopyright" -> naiveEscapeProperty p
-      _           -> warn $ "unknown tileset property " <> prettyprint name
+      "collides"         -> warn "property \"collides\" should be set on individual tiles, not the tileset"
+      _                  -> warn $ "unknown tileset property " <> prettyprint name
 
     checkTile :: Tile -> LintWriter Tileset
     checkTile tile = do