diff --git a/src/GEval/Core.hs b/src/GEval/Core.hs
index 69ebe74..e683a1b 100644
--- a/src/GEval/Core.hs
+++ b/src/GEval/Core.hs
@@ -40,7 +40,8 @@ module GEval.Core
       checkMultipleOutsCore,
       gesMainMetric,
       gesPreprocess,
-      getDataDecoder
+      getDataDecoder,
+      threeLineSource
     ) where
 
 import Data.Conduit
@@ -951,7 +952,11 @@ instance (MonadUnliftIO m, MonadIO m, MonadThrow m) => EvaluationContext (WithIn
   checkStepM _ (_, WrappedParsedRecordWithInput Done Done Done) = return Nothing
 
 
-
+threeLineSource :: (MonadUnliftIO m, MonadIO m, MonadThrow m) => WithInput m Text Text Text -> ConduitT () (WrappedParsedRecord (WithInput m Text Text Text)) (ResourceT m) ()
+threeLineSource (WithInput inputLineSource expectedLineSource outLineSource) = getZipSource $ (\x (y,z) -> WrappedParsedRecordWithInput x y z)
+         <$> ZipSource (linesAsItems inputLineSource)                                             <*> (ZipSource $ getZipSource $ (,)
+                        <$> ZipSource (linesAsItems expectedLineSource)
+                        <*> ZipSource (linesAsItems outLineSource))
 
 averageC :: MonadResource m => ConduitT Double Void m Double
 averageC = getZipSink
@@ -959,6 +964,8 @@ averageC = getZipSink
   <$> ZipSink CC.sum
   <*> ZipSink CC.length
 
+-- | Takes a source of lines and returns a source of lines and returns a conduit of
+-- items (using a given preprocessor and parser).
 items :: MonadResource m => LineSource m -> (ItemTarget -> Either String a) -> ConduitT () (SourceItem a) m ()
 items (LineSource lineSource itemDecoder preprocess _ _) parser =
   (lineSource .| CL.map (toItem . parser . preprocess' . itemDecoder)) >> yield Done
@@ -967,6 +974,12 @@ items (LineSource lineSource itemDecoder preprocess _ _) parser =
         preprocess' (RawItemTarget t) = RawItemTarget $ preprocess t
         preprocess' (PartiallyParsedItemTarget ts) = PartiallyParsedItemTarget $ Prelude.map preprocess ts
 
+-- | Takes a source of lines and returns a conduit of lines represented as
+-- items (without preprocessing and parsing!) to be used in line-by-line modes.
+linesAsItems :: MonadResource m => LineSource m -> ConduitT () (SourceItem Text) m ()
+linesAsItems (LineSource lineSource _ _ _ _) =
+  (lineSource .| CL.map Got) >> yield Done
+
 itemAbsoluteError :: (Double, Double) -> Double
 itemAbsoluteError (exp, out) = abs (exp-out)
 
diff --git a/src/GEval/LineByLine.hs b/src/GEval/LineByLine.hs
index 60a96e7..ea33b82 100644
--- a/src/GEval/LineByLine.hs
+++ b/src/GEval/LineByLine.hs
@@ -420,9 +420,9 @@ gevalLineByLineSource :: Metric -> Maybe Selector -> (Text -> Text) -> SourceSpe
 gevalLineByLineSource metric mSelector preprocess inputSource expectedSource outSource =
   (getZipSource $ (,)
        <$> ZipSource (CL.sourceList [1..])
-       <*> (ZipSource $ recordSource context parserSpec)) .| CL.mapM (checkStepM evaluateLine) .| CL.catMaybes
-  where parserSpec = (ParserSpecWithInput (Right . id) (Right . id) (Right . id))
-        context = (WithInput inputLineSource expectedLineSource outputLineSource)
+       <*> (ZipSource $ threeLineSource context)) .| CL.mapM (checkStepM evaluateLine) .| CL.catMaybes
+  where context = (WithInput inputLineSource expectedLineSource outputLineSource)
+        -- preparing sources, `id` means that no preprocessing is done (to avoid double preprocessing)
         inputLineSource = fileAsLineSource inputSource mSelector id
         expectedLineSource = fileAsLineSource expectedSource mSelector id
         outputLineSource = fileAsLineSource outSource mSelector id
diff --git a/test/Spec.hs b/test/Spec.hs
index c835830..0f11a95 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -23,6 +23,7 @@ import Text.EditDistance
 import GEval.Annotation
 import GEval.BlackBoxDebugging
 import GEval.FeatureExtractor
+import GEval.Selector
 
 import Data.Map.Strict
 
@@ -287,8 +288,11 @@ main = hspec $ do
       runGEvalTest "multilabel-likelihood-simple" `shouldReturnAlmost` 0.115829218528827
   describe "evaluating single lines" $ do
     it "RMSE" $ do
-      gevalCoreOnSingleLines RMSE id (LineInFile (FilePathSpec "stub1") 1 "blabla")
+      gevalCoreOnSingleLines RMSE id RawItemTarget
+                                     (LineInFile (FilePathSpec "stub1") 1 "blabla")
+                                     RawItemTarget
                                      (LineInFile (FilePathSpec "stub2") 1 "3.4")
+                                     RawItemTarget
                                      (LineInFile (FilePathSpec "stub3") 1 "2.6") `shouldReturnAlmost` 0.8
   describe "Annotation format" $ do
     it "just parse" $ do