diff --git a/Text/PrettyPrint/Mainland.hs b/Text/PrettyPrint/Mainland.hs
--- a/Text/PrettyPrint/Mainland.hs
+++ b/Text/PrettyPrint/Mainland.hs
@@ -453,12 +453,12 @@
   where
     go :: RDoc -> ShowS
     go REmpty          = id
-    go (RChar c x)     = showChar c `mappend` go x
-    go (RString _ s x) = showString s `mappend` go x
-    go (RText s x)     = showString (T.unpack s) `mappend` go x
-    go (RLazyText s x) = showString (L.unpack s) `mappend` go x
+    go (RChar c x)     = showChar c . go x
+    go (RString _ s x) = showString s . go x
+    go (RText s x)     = showString (T.unpack s) . go x
+    go (RLazyText s x) = showString (L.unpack s) . go x
     go (RPos _ x)      = go x
-    go (RLine i x)     = showString ('\n' : replicate i ' ') `mappend` go x
+    go (RLine i x)     = showString ('\n' : replicate i ' ') . go x
 
 -- | Render and display a document.
 prettyS :: Int -> Doc -> ShowS
@@ -474,17 +474,17 @@
   where
     go :: RDoc -> ShowS
     go REmpty          = id
-    go (RChar c x)     = showChar c `mappend` go x
-    go (RString _ s x) = showString s `mappend` go x
-    go (RText s x)     = showString (T.unpack s) `mappend` go x
-    go (RLazyText s x) = showString (L.unpack s) `mappend` go x
-    go (RPos p x)      = showChar '\n' `mappend`
-                         showString "#line " `mappend`
-                         shows (posLine p) `mappend`
-                         showChar ' ' `mappend`
-                         shows (posFile p) `mappend`
+    go (RChar c x)     = showChar c . go x
+    go (RString _ s x) = showString s . go x
+    go (RText s x)     = showString (T.unpack s) . go x
+    go (RLazyText s x) = showString (L.unpack s) . go x
+    go (RPos p x)      = showChar '\n' .
+                         showString "#line " .
+                         shows (posLine p) .
+                         showChar ' ' .
+                         shows (posFile p) .
                          go x
-    go (RLine i x)     = showString ('\n' : replicate i ' ') `mappend`
+    go (RLine i x)     = showString ('\n' : replicate i ' ') .
                          go x
 
 -- | Render and display a document with #line pragmas.
diff --git a/mainland-pretty.cabal b/mainland-pretty.cabal
--- a/mainland-pretty.cabal
+++ b/mainland-pretty.cabal
@@ -1,5 +1,5 @@
 name:           mainland-pretty
-version:        0.2.6
+version:        0.2.7
 cabal-version:  >= 1.6
 license:        BSD3
 license-file:   LICENSE
@@ -28,7 +28,7 @@
     base       >= 4    && < 5,
     containers >= 0.2  && < 0.6,
     srcloc     >= 0.2  && < 0.5,
-    text       >  0.11 && < 0.12
+    text       >  0.11 && < 1.2
 
 source-repository head
   type:     git