diff --git a/Yesod/Routes/Overlap.hs b/Yesod/Routes/Overlap.hs
--- a/Yesod/Routes/Overlap.hs
+++ b/Yesod/Routes/Overlap.hs
@@ -8,15 +8,42 @@
 import Yesod.Routes.TH.Types
 import Data.List (intercalate)
 
+data Flattened t = Flattened
+    { fNames :: [String]
+    , fPieces :: [(CheckOverlap, Piece t)]
+    , fHasSuffix :: Bool
+    }
+
+flatten :: ResourceTree t -> [Flattened t]
+flatten =
+    go id id
+  where
+    go names pieces (ResourceLeaf r) = return Flattened
+        { fNames = names [resourceName r]
+        , fPieces = pieces (resourcePieces r)
+        , fHasSuffix = hasSuffix $ ResourceLeaf r
+        }
+    go names pieces (ResourceParent newname newpieces children) =
+        concatMap (go names' pieces') children
+      where
+        names' = names . (newname:)
+        pieces' = pieces . (newpieces ++)
+
 data Overlap t = Overlap
     { overlapParents :: [String] -> [String] -- ^ parent resource trees
     , overlap1 :: ResourceTree t
     , overlap2 :: ResourceTree t
     }
 
+data OverlapF = OverlapF
+    { overlapF1 :: [String]
+    , overlapF2 :: [String]
+    }
+
 findOverlaps :: ([String] -> [String]) -> [ResourceTree t] -> [Overlap t]
 findOverlaps _ [] = []
 findOverlaps front (x:xs) = concatMap (findOverlap front x) xs ++ findOverlaps front xs
+{-# DEPRECATED findOverlaps "This function is no longer used" #-}
 
 findOverlap :: ([String] -> [String]) -> ResourceTree t -> ResourceTree t -> [Overlap t]
 findOverlap front x y =
@@ -30,14 +57,6 @@
             ResourceParent name _ children -> findOverlaps (front . (name:)) children
             ResourceLeaf{} -> []
 
-hasSuffix :: ResourceTree t -> Bool
-hasSuffix (ResourceLeaf r) =
-    case resourceDispatch r of
-        Subsite{} -> True
-        Methods Just{} _ -> True
-        Methods Nothing _ -> False
-hasSuffix ResourceParent{} = True
-
 overlaps :: [(CheckOverlap, Piece t)] -> [(CheckOverlap, Piece t)] -> Bool -> Bool -> Bool
 
 -- No pieces on either side, will overlap regardless of suffix
@@ -66,9 +85,26 @@
 
 findOverlapNames :: [ResourceTree t] -> [(String, String)]
 findOverlapNames =
-    map go . findOverlaps id
+    map go . findOverlapsF . concatMap Yesod.Routes.Overlap.flatten
   where
-    go (Overlap front x y) =
-        (go' $ resourceTreeName x, go' $ resourceTreeName y)
+    go (OverlapF x y) =
+        (go' x, go' y)
       where
-        go' = intercalate "/" . front . return
+        go' = intercalate "/"
+
+findOverlapsF :: [Flattened t] -> [OverlapF]
+findOverlapsF [] = []
+findOverlapsF (x:xs) = concatMap (findOverlapF x) xs ++ findOverlapsF xs
+
+findOverlapF :: Flattened t -> Flattened t -> [OverlapF]
+findOverlapF x y
+    | overlaps (fPieces x) (fPieces y) (fHasSuffix x) (fHasSuffix y) = [OverlapF (fNames x) (fNames y)]
+    | otherwise = []
+
+hasSuffix :: ResourceTree t -> Bool
+hasSuffix (ResourceLeaf r) =
+    case resourceDispatch r of
+        Subsite{} -> True
+        Methods Just{} _ -> True
+        Methods Nothing _ -> False
+hasSuffix ResourceParent{} = True
diff --git a/Yesod/Routes/Parse.hs b/Yesod/Routes/Parse.hs
--- a/Yesod/Routes/Parse.hs
+++ b/Yesod/Routes/Parse.hs
@@ -29,7 +29,7 @@
         let res = resourcesFromString s
         case findOverlapNames res of
             [] -> lift res
-            z -> error $ "Overlapping routes: " ++ unlines (map show z)
+            z -> error $ unlines $ "Overlapping routes: " : map show z
 
 parseRoutesFile :: FilePath -> Q Exp
 parseRoutesFile = parseRoutesFileWith parseRoutes
diff --git a/test/Hierarchy.hs b/test/Hierarchy.hs
--- a/test/Hierarchy.hs
+++ b/test/Hierarchy.hs
@@ -71,7 +71,6 @@
     -> App sub master
 runHandler h Env {..} route _ = (toText h, fmap envToMaster route)
 
-
 data Hierarchy = Hierarchy
 
 do
@@ -79,13 +78,29 @@
 / HomeR GET
 
 /admin/#Int AdminR:
-    / AdminRootR GET
-    /login LoginR GET POST
-    /table/#Text TableR GET
+    /            AdminRootR GET
+    /login       LoginR     GET POST
+    /table/#Text TableR     GET
 
 /nest/ NestR:
 
   /spaces      SpacedR   GET
+
+  /nest2 Nest2:
+    /get        Get2      GET
+    /post       Post2         POST
+--    /#Int       Delete2            DELETE
+  /nest3 Nest3:
+    /get        Get3      GET
+    /post       Post3         POST
+--    /#Int       Delete3            DELETE
+
+/afterwards AfterR:
+  /             After     GET
+
+-- /trailing-nest TrailingNestR:
+--  /foo TrailingFooR GET
+--  /#Int TrailingIntR GET
 |]
 
     rrinst <- mkRenderRouteInstance (ConT ''Hierarchy) $ map (fmap parseType) resources
@@ -112,6 +127,15 @@
 
 getSpacedR :: Handler site String
 getSpacedR = "root-leaf"
+
+getGet2   :: Handler site String; getGet2 = "get"
+postPost2 :: Handler site String; postPost2 = "post"
+deleteDelete2 :: Int -> Handler site String; deleteDelete2 = const "delete"
+getGet3   :: Handler site String; getGet3 = "get"
+postPost3 :: Handler site String; postPost3 = "post"
+deleteDelete3   :: Int -> Handler site String; deleteDelete3 = const "delete"
+
+getAfter   :: Handler site String; getAfter = "after"
 
 getHomeR :: Handler site String
 getHomeR = "home"
diff --git a/yesod-routes.cabal b/yesod-routes.cabal
--- a/yesod-routes.cabal
+++ b/yesod-routes.cabal
@@ -1,5 +1,5 @@
 name:            yesod-routes
-version:         1.2.0.3
+version:         1.2.0.4
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>