diff --git a/src/Development/IDE/Core/RuleTypes.hs b/src/Development/IDE/Core/RuleTypes.hs
index 39d63a8ac0..b822d03f2f 100644
--- a/src/Development/IDE/Core/RuleTypes.hs
+++ b/src/Development/IDE/Core/RuleTypes.hs
@@ -61,6 +61,9 @@ type instance RuleResult GetKnownFiles = HS.HashSet NormalizedFilePath
 -- that module.
 data TcModuleResult = TcModuleResult
     { tmrModule     :: TypecheckedModule
+    -- ^ warning, the ModIface in the tm_checked_module_info of the
+    -- TypecheckedModule will always be Nothing, use the ModIface in the
+    -- HomeModInfo instead
     , tmrModInfo    :: HomeModInfo
     , tmrDeferedError :: !Bool -- ^ Did we defer any type errors for this module?
     }
diff --git a/src/Development/IDE/Core/Rules.hs b/src/Development/IDE/Core/Rules.hs
index a0928b11aa..0f69efe08e 100644
--- a/src/Development/IDE/Core/Rules.hs
+++ b/src/Development/IDE/Core/Rules.hs
@@ -233,6 +233,12 @@ priorityGenerateCore = Priority (-1)
 priorityFilesOfInterest :: Priority
 priorityFilesOfInterest = Priority (-2)
 
+-- | IMPORTANT FOR HLINT INTEGRATION:
+-- We currently parse the module both with and without Opt_Haddock, and
+-- return the one with Haddocks if it -- succeeds. However, this may not work
+-- for hlint, and we might need to save the one without haddocks too.
+-- See https://github.com/digital-asset/ghcide/pull/350#discussion_r370878197
+-- and https://github.com/mpickering/ghcide/pull/22#issuecomment-625070490
 getParsedModuleRule :: Rules ()
 getParsedModuleRule = defineEarlyCutoff $ \GetParsedModule file -> do
     sess <- use_ GhcSession file
@@ -251,18 +257,28 @@ getParsedModuleRule = defineEarlyCutoff $ \GetParsedModule file -> do
         then
             liftIO mainParse
         else do
-            let haddockParse = do
-                    (_, (!diagsHaddock, _)) <-
-                        getParsedModuleDefinition (withOptHaddock hsc) opt comp_pkgs file modTime contents
-                    return diagsHaddock
-
-            ((fingerPrint, (diags, res)), diagsHaddock) <-
-                -- parse twice, with and without Haddocks, concurrently
-                -- we want warnings if parsing with Haddock fails
-                -- but if we parse with Haddock we lose annotations
-                liftIO $ concurrently mainParse haddockParse
-
-            return (fingerPrint, (mergeParseErrorsHaddock diags diagsHaddock, res))
+            let haddockParse = getParsedModuleDefinition (withOptHaddock hsc) opt comp_pkgs file modTime contents
+
+            -- parse twice, with and without Haddocks, concurrently
+            -- we cannot ignore Haddock parse errors because files of
+            -- non-interest are always parsed with Haddocks
+            -- If we can parse Haddocks, might as well use them
+            --
+            -- HLINT INTEGRATION: might need to save the other parsed module too
+            ((fp,(diags,res)),(fph,(diagsh,resh))) <- liftIO $ concurrently mainParse haddockParse
+
+            -- Merge haddock and regular diagnostics so we can always report haddock
+            -- parse errors
+            let diagsM = mergeParseErrorsHaddock diags diagsh
+            case resh of
+              Just _
+                | HaddockParse <- optHaddockParse opt
+                -> pure (fph, (diagsM, resh))
+              -- If we fail to parse haddocks, report the haddock diagnostics as well and
+              -- return the non-haddock parse.
+              -- This seems to be the correct behaviour because the Haddock flag is added
+              -- by us and not the user, so our IDE shouldn't stop working because of it.
+              _ -> pure (fp, (diagsM, res))
 
 
 withOptHaddock :: HscEnv -> HscEnv
@@ -281,7 +297,6 @@ mergeParseErrorsHaddock normal haddock = normal ++
     fixMessage x | "parse error " `T.isPrefixOf` x = "Haddock " <> x
                  | otherwise = "Haddock: " <> x
 
-
 getParsedModuleDefinition :: HscEnv -> IdeOptions -> [PackageName] -> NormalizedFilePath -> UTCTime -> Maybe T.Text -> IO (Maybe ByteString, ([FileDiagnostic], Maybe ParsedModule))
 getParsedModuleDefinition packageState opt comp_pkgs file modTime contents = do
     let fp = fromNormalizedFilePath file
diff --git a/src/Development/IDE/Types/Options.hs b/src/Development/IDE/Types/Options.hs
index 7ab60b7752..ecc9cec1b2 100644
--- a/src/Development/IDE/Types/Options.hs
+++ b/src/Development/IDE/Types/Options.hs
@@ -24,6 +24,7 @@ module Development.IDE.Types.Options
   , defaultLspConfig
   , CheckProject(..)
   , CheckParents(..)
+  , OptHaddockParse(..)
   ) where
 
 import Development.Shake
@@ -88,8 +89,16 @@ data IdeOptions = IdeOptions
     -- ^ Whether to typecheck the entire project on load
   , optCheckParents :: CheckParents
     -- ^ When to typecheck reverse dependencies of a file
+  , optHaddockParse :: OptHaddockParse
+    -- ^ Whether to return result of parsing module with Opt_Haddock.
+    --   Otherwise, return the result of parsing without Opt_Haddock, so
+    --   that the parsed module contains the result of Opt_KeepRawTokenStream,
+    --   which might be necessary for hlint.
   }
 
+data OptHaddockParse = HaddockParse | NoHaddockParse
+  deriving (Eq,Ord,Show,Enum)
+
 newtype CheckProject = CheckProject { shouldCheckProject :: Bool }
   deriving stock (Eq, Ord, Show)
   deriving newtype (FromJSON,ToJSON)
@@ -147,6 +156,7 @@ defaultIdeOptions session = IdeOptions
     ,optTesting = IdeTesting False
     ,optCheckProject = checkProject defaultLspConfig
     ,optCheckParents = checkParents defaultLspConfig
+    ,optHaddockParse = HaddockParse
     }
 
 
diff --git a/test/exe/Main.hs b/test/exe/Main.hs
index f67f2b38ad..e7fe89c79b 100644
--- a/test/exe/Main.hs
+++ b/test/exe/Main.hs
@@ -2186,7 +2186,7 @@ findDefinitionAndHoverTests = let
   , test  yes    yes    mclL36     mcl           "top-level fn 1st clause"
   , test  yes    yes    mclL37     mcl           "top-level fn 2nd clause         #246"
   , test  yes    yes    spaceL37   space        "top-level fn on space #315"
-  , test  no     broken docL41     doc           "documentation                     #7"
+  , test  no     yes    docL41     doc           "documentation                     #7"
   , test  no     yes    eitL40     kindE         "kind of Either                  #273"
   , test  no     yes    intL40     kindI         "kind of Int                     #273"
   , test  no     broken tvrL40     kindV         "kind of (* -> *) type variable  #273"