diff --git a/core/GhcMod/DynFlags.hs b/core/GhcMod/DynFlags.hs
index 4bb1f24..5caa072 100644
--- a/core/GhcMod/DynFlags.hs
+++ b/core/GhcMod/DynFlags.hs
@@ -104,6 +104,5 @@ deferErrors df = return $
 
 deriveEqDynFlags [d|
   eqDynFlags :: DynFlags -> DynFlags -> [[(Bool, String)]]
-  -- eqDynFlags :: DynFlags -> DynFlags -> ([Bool], [String])
   eqDynFlags = undefined
  |]
diff --git a/core/GhcMod/DynFlagsTH.hs b/core/GhcMod/DynFlagsTH.hs
index 206a75e..fbcee1f 100644
--- a/core/GhcMod/DynFlagsTH.hs
+++ b/core/GhcMod/DynFlagsTH.hs
@@ -14,7 +14,6 @@
 -- You should have received a copy of the GNU Affero General Public License
 -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-{-# OPTIONS_GHC -fno-warn-orphans #-}
 {-# LANGUAGE CPP, TemplateHaskell #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE DeriveDataTypeable #-}
@@ -45,10 +44,6 @@ deriveEqDynFlags qds = do
   a <- newName "a"
   b <- newName "b"
 
-  -- let combFunc = [| \(bs,ss) -> (and bs, unwords ss) |]
-
-  -- e <- AppE (VarE 'and) . ListE <$> sequence (mapMaybe (eq a b) fs)
-  -- e <- AppE (combFunc) . ListE <$> sequence $ combFunc (catMaybes $ map (eq a b) fs)
   e <- ListE <$> sequence (mapMaybe (eq a b) fs)
 
   tysig@(SigD n _) :_ <- qds
@@ -103,8 +98,6 @@ deriveEqDynFlags qds = do
                [e| $(eqfn) $(return fa) $(return fb) |]
 
            "extraPkgConfs" -> do
-               -- let eqfn = [| let fn a' b' = and (zipWith eqpr (a' []) (b' []))
-               --                          && length (a' []) == length (b' [])
                let eqfn = [| let fn a' b' = cond a' b'
 
                                  cond a' b' = zz ++ ll
@@ -159,6 +152,13 @@ deriveEqDynFlags qds = do
                [e| $(eqfn) $(return fa) $(return fb) |]
 #endif
 
+           "outputFile" -> do
+               let eqfn = [| let fn (Just f1) (Just f2) = [(f1 == f2, if f1 == f2 then "" else "outputFile changed")]
+                                 fn _ _ = [(True, "")] -- anything with a Nothing is fine.
+                             in fn
+                          |]
+               [e| $(eqfn) $(return fa) $(return fb) |]
+
            "generalFlags" -> checkIntSet "generalFlags"
 
            "warningFlags" -> checkIntSet "warningFlags"
diff --git a/core/GhcMod/Target.hs b/core/GhcMod/Target.hs
index 6d0d318..0523fc6 100644
--- a/core/GhcMod/Target.hs
+++ b/core/GhcMod/Target.hs
@@ -86,9 +86,9 @@ initSession opts mdf = do
          df <- liftIO $ hsc_dflags <$> readIORef hsc_env_ref
          changed <-
              withLightHscEnv' (initDF crdl) $ \hsc_env -> do
+               gmLog GmDebug "initSession" $ text $ "outputFiles:" ++ show (outputFile $ hsc_dflags hsc_env, outputFile df)
                let dfEq = concat $ hsc_dflags hsc_env `eqDynFlags` df
                gmLog GmDebug "initSession" $ text $ "dfEq=" ++ (show $ filter (\t -> not (fst t)) dfEq)
-               -- gmLog GmDebug "initSession" $ text $ "dfEq=" ++ (show  dfEq)
                let eq = and $ map fst dfEq
                -- return $ not $ hsc_dflags hsc_env `eqDynFlags` df
                return $ not eq