I am trying to develop two similar route one that takes a constant string value as its last argument and one that takes a integer as its last argument /admin/#String/add ModelAddR GET /admin/#String/#Int ModelEditR GET I would expect that there should be no conflict and that the first should take precedence. However I get the following error. Exception when trying to run compile-time code: Overlapping routes: (Resource "ModelAddR" [StaticPiece "admin",SinglePiece "String",StaticPiece "add"] ["GET"],Resource "ModelEditR" [StaticPiece "admin",SinglePiece "String",SinglePiece "Int"] ["GET"]) Is this a limitation of Yesod or a bug? The following seems to work fine. /admin/#String/add ModelAddR GET /admin/#String/edit/#Int ModelEditR GET