diff --git a/HLint.hs b/HLint.hs
index 0386f6ffd..1ac62bf71 100644
--- a/HLint.hs
+++ b/HLint.hs
@@ -2,6 +2,8 @@ import "hint" HLint.Default
 import "hint" HLint.Dollar
 import "hint" HLint.Generalise
 
+ignore "Use mappend"
+error "generalize ++" = (++) ==> (<>)
 -- AMP fallout
 error "generalize mapM"  = mapM  ==> traverse
 error "generalize mapM_" = mapM_ ==> traverse_
diff --git a/src/Alignment.hs b/src/Alignment.hs
index 59ecab355..d9078a644 100644
--- a/src/Alignment.hs
+++ b/src/Alignment.hs
@@ -133,11 +133,11 @@ alignChildren getRange (first:rest) headRanges
   | ~(l, r) <- splitThese first
   = case intersectionsWithHeadRanges first of
     -- It intersects on both sides, so we can just take the first line whole.
-    (True, True) -> ((++) <$> toTerms first <*> firstRemaining, restRemaining)
+    (True, True) -> ((<>) <$> toTerms first <*> firstRemaining, restRemaining)
     -- It only intersects on the left, so split it up.
-    (True, False) -> ((++) <$> toTerms (fromJust l) <*> firstRemaining, maybe identity (:) r restRemaining)
+    (True, False) -> ((<>) <$> toTerms (fromJust l) <*> firstRemaining, maybe identity (:) r restRemaining)
     -- It only intersects on the right, so split it up.
-    (False, True) -> ((++) <$> toTerms (fromJust r) <*> firstRemaining, maybe identity (:) l restRemaining)
+    (False, True) -> ((<>) <$> toTerms (fromJust r) <*> firstRemaining, maybe identity (:) l restRemaining)
     -- It doesn’t intersect at all, so skip it and move along.
     (False, False) -> (firstRemaining, first:restRemaining)
   | otherwise = alignChildren getRange rest headRanges
diff --git a/src/Parser.hs b/src/Parser.hs
index eef533422..8ac8e9070 100644
--- a/src/Parser.hs
+++ b/src/Parser.hs
@@ -42,7 +42,7 @@ termConstructor source info = cofree . construct
   where
     withDefaultInfo syntax = (info :< syntax)
     construct :: [Term Text Info] -> CofreeF (S.Syntax Text) Info (Term Text Info)
-    construct [] = withDefaultInfo $ S.Leaf . pack . toString $ slice (characterRange info) source
+    construct [] = withDefaultInfo . S.Leaf . pack . toString $ slice (characterRange info) source
     construct children | Assignment == category info = case children of
       (identifier:value:[]) -> withDefaultInfo $ S.Assignment identifier value
     construct children | MathAssignment == category info = case children of
diff --git a/src/Range.hs b/src/Range.hs
index 206f7c38e..57984634c 100644
--- a/src/Range.hs
+++ b/src/Range.hs
@@ -35,7 +35,7 @@ rangesAndWordsFrom startIndex string = fromMaybe [] $ take isWord <|> take isPun
     endFor parsed = startIndex + length parsed
     parse transform predicate = case span predicate string of
       ([], _) -> Nothing
-      (parsed, rest) -> Just $ maybe identity (:) (transform parsed) $ rangesAndWordsFrom (endFor parsed) rest
+      (parsed, rest) -> Just . maybe identity (:) (transform parsed) $ rangesAndWordsFrom (endFor parsed) rest
     -- | Is this a word character?
     -- | Word characters are defined as in [Ruby’s `\p{Word}` syntax](http://ruby-doc.org/core-2.1.1/Regexp.html#class-Regexp-label-Character+Properties), i.e.:
     -- | > A member of one of the following Unicode general category _Letter_, _Mark_, _Number_, _Connector_Punctuation_
diff --git a/src/Renderer/Split.hs b/src/Renderer/Split.hs
index 012f0e3ab..43c5cf584 100644
--- a/src/Renderer/Split.hs
+++ b/src/Renderer/Split.hs
@@ -80,7 +80,7 @@ split diff blobs = TL.toStrict . renderHtml
   . docTypeHtml
     . ((head $ link ! A.rel "stylesheet" ! A.href "style.css") <>)
     . body
-      . (table ! A.class_ (stringValue "diff")) $
+      . (table ! A.class_ (stringValue "diff")) .
         ((colgroup $ (col ! A.width (stringValue . show $ columnWidth)) <> col <> (col ! A.width (stringValue . show $ columnWidth)) <> col) <>)
         . mconcat $ numberedLinesToMarkup <$> numbered
   where
@@ -158,7 +158,7 @@ instance ToMarkup (Renderable (Source Char, Term a Info)) where
   toMarkup (Renderable (source, term)) = Prologue.fst $ cata (\ (info :< syntax) -> (toMarkup $ Renderable (source, info, syntax), characterRange info)) term
 
 instance ToMarkup (Renderable (Source Char, SplitDiff a Info)) where
-  toMarkup (Renderable (source, diff)) = Prologue.fst $ iter (\ (info :< syntax) -> (toMarkup $ Renderable (source, info, syntax), characterRange info)) $ toMarkupAndRange <$> diff
+  toMarkup (Renderable (source, diff)) = Prologue.fst . iter (\ (info :< syntax) -> (toMarkup $ Renderable (source, info, syntax), characterRange info)) $ toMarkupAndRange <$> diff
     where toMarkupAndRange :: SplitPatch (Term a Info) -> (Markup, Range)
           toMarkupAndRange patch = let term@(info :< _) = runCofree $ getSplitTerm patch in
             ((div ! A.class_ (splitPatchToClassName patch) ! A.data_ (stringValue (show (unSize (size info))))) . toMarkup $ Renderable (source, cofree term), characterRange info)