diff --git a/Language/Haskell/GhcMod/ErrMsg.hs b/Language/Haskell/GhcMod/ErrMsg.hs
index 637e7ed..548ca22 100644
--- a/Language/Haskell/GhcMod/ErrMsg.hs
+++ b/Language/Haskell/GhcMod/ErrMsg.hs
@@ -81,7 +81,7 @@ ppMsg spn sev dflag ls@(LineSeparator lsep) msg = prefix ++ cts ++ lsep
     cts  = showMsg dflag ls msg
     defaultPrefix
       | dopt Opt_D_dump_splices dflag = ""
-      | otherwise                     = "Dummy:0:0:"
+      | otherwise                     = "Dummy:0:0:Error:"
     prefix = fromMaybe defaultPrefix $ do
         (line,col,_,_) <- Gap.getSrcSpan spn
         file <- normalise <$> Gap.getSrcFile spn
diff --git a/Language/Haskell/GhcMod/GHCApi.hs b/Language/Haskell/GhcMod/GHCApi.hs
index 4415149..d43265b 100644
--- a/Language/Haskell/GhcMod/GHCApi.hs
+++ b/Language/Haskell/GhcMod/GHCApi.hs
@@ -6,6 +6,7 @@ module Language.Haskell.GhcMod.GHCApi (
   , initializeFlags
   , initializeFlagsWithCradle
   , setTargetFiles
+  , addTargetFiles
   , getDynamicFlags
   ) where
 
@@ -157,6 +158,12 @@ setTargetFiles files = do
     targets <- forM files $ \file -> guessTarget file Nothing
     setTargets targets
 
+addTargetFiles :: (GhcMonad m) => [FilePath] -> m ()
+addTargetFiles [] = error "ghc-mod: addTargetFiles: No target files given"
+addTargetFiles files = do
+    targets <- forM files $ \file -> guessTarget file Nothing
+    mapM_ addTarget targets
+
 ----------------------------------------------------------------
 
 -- | Return the 'DynFlags' currently in use in the GHC session.
diff --git a/Language/Haskell/GhcMod/Internal.hs b/Language/Haskell/GhcMod/Internal.hs
index fbeda09..9908fc4 100644
--- a/Language/Haskell/GhcMod/Internal.hs
+++ b/Language/Haskell/GhcMod/Internal.hs
@@ -21,6 +21,8 @@ module Language.Haskell.GhcMod.Internal (
   , initializeFlagsWithCradle
   -- * 'GhcMonad'
   , setTargetFiles
+  , addTargetFiles
+  , handleErrMsg
   -- * 'Ghc' Choice
   , (||>)
   , goNext