diff --git a/CHANGES.txt b/CHANGES.txt
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,5 +1,7 @@
 Changelog for Weeder
 
+0.1.6
+    #10, find files generated by alex/happy
 0.1.5
     If --yaml and no hints give no output
 0.1.4
diff --git a/src/Cabal.hs b/src/Cabal.hs
--- a/src/Cabal.hs
+++ b/src/Cabal.hs
@@ -27,9 +27,9 @@
         [x] -> return x
         _ -> fail $ "Didn't find exactly 1 cabal file in " ++ dir
 
--- | Return the (exposed Hi files, internal Hi files)
-selectHiFiles :: Map.HashMap FilePath a -> CabalSection -> ([a], [a], [ModuleName])
-selectHiFiles his sect@CabalSection{..} = (external, internal, bad1++bad2)
+-- | Return the (exposed Hi files, internal Hi files, not found)
+selectHiFiles :: FilePath -> Map.HashMap FilePath a -> CabalSection -> ([a], [a], [ModuleName])
+selectHiFiles distDir his sect@CabalSection{..} = (external, internal, bad1++bad2)
     where
         (bad1, external) = partitionEithers $
             [findHi his sect $ Left cabalMainIs | cabalMainIs /= ""] ++
@@ -42,8 +42,10 @@
             where
                 mname = either takeFileName id name
                 poss = [ normalise $ joinPath (root : x : either (return . dropExtension) (splitOn ".") name) <.> "dump-hi"
-                    | root <- ["build" </> x </> (x ++ "-tmp") | Just x <- [cabalSectionTypeName cabalSectionType]] ++ ["build"]
-                    , x <- if null cabalSourceDirs then ["."] else cabalSourceDirs]
+                    | extra <- [".",distDir]
+                    , root <- ["build" </> extra </> x </> (x ++ "-tmp") | Just x <- [cabalSectionTypeName cabalSectionType]] ++
+                              ["build", "build" </> distDir </> "build"]
+                    , x <- cabalSourceDirs ++ ["."]]
 
 
 data Cabal = Cabal
diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -47,7 +47,7 @@
     res <- forM cabals $ \(cabalFile, Cabal{..}) -> do
         (fileToKey, keyToHi) <- hiParseDirectory $ takeDirectory cabalFile </> stackDistDir
         let full = check (keyToHi Map.!) cabalName $
-                   map (id &&& selectHiFiles fileToKey) cabalSections
+                   map (id &&& selectHiFiles stackDistDir fileToKey) cabalSections
         let warn = if cmdShowAll || cmdMatch then full else ignoreWarnings ignore full
         unless quiet $
             putStrLn $ unlines $ showWarningsPretty cabalName warn
diff --git a/weeder.cabal b/weeder.cabal
--- a/weeder.cabal
+++ b/weeder.cabal
@@ -1,7 +1,7 @@
 cabal-version:      >= 1.18
 build-type:         Simple
 name:               weeder
-version:            0.1.5
+version:            0.1.6
 license:            BSD3
 license-file:       LICENSE
 category:           Development