diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,17 @@
+5.2.12
+  - unreleased
+
+5.2.11
+  - deepseq bounds increased for tests.
+  - Clean up warnings when compiling on 7.10
+    - Thanks Eric Mertens
+  - Avoid discarding input bytes after multi-byte encoded codepoint
+    - Thanks Eric Mertens
+
+5.2.10
+  - "str" now returns EmptyImage for empty strings to match behavior of other string-like Image constructors (fixes #74)
+    - Thanks Jonathan Daugherty
+
 5.2.9
   - dependency version bumps
     - https://github.com/coreyoconnor/vty/pull/71
diff --git a/src/Data/Terminfo/Eval.hs b/src/Data/Terminfo/Eval.hs
--- a/src/Data/Terminfo/Eval.hs
+++ b/src/Data/Terminfo/Eval.hs
@@ -1,7 +1,13 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# OPTIONS_GHC -funbox-strict-fields #-}
 {-# OPTIONS_HADDOCK hide #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 {- Evaluates the paramaterized terminfo string capability with the given parameters.
  -
  -}
@@ -17,10 +23,13 @@
 import Control.Monad.Writer
 
 import Data.Bits ((.|.), (.&.), xor)
-import Data.List 
-import Data.Word 
+import Data.List
 
 import qualified Data.Vector.Unboxed as Vector
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Word
+#endif
 
 -- | capability evaluator state
 data EvalState = EvalState
diff --git a/src/Data/Terminfo/Parse.hs b/src/Data/Terminfo/Parse.hs
--- a/src/Data/Terminfo/Parse.hs
+++ b/src/Data/Terminfo/Parse.hs
@@ -1,8 +1,14 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 {-# OPTIONS_HADDOCK hide #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# OPTIONS_GHC -funbox-strict-fields -O #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 module Data.Terminfo.Parse ( module Data.Terminfo.Parse
                            , Text.Parsec.ParseError
                            )
@@ -11,13 +17,16 @@
 import Control.Monad ( liftM )
 import Control.DeepSeq
 
-import Data.Monoid
 import Data.Word
 import qualified Data.Vector.Unboxed as Vector
 
 import Numeric (showHex)
 
 import Text.Parsec
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid
+#endif
 
 data CapExpression = CapExpression
     { capOps :: !CapOps
diff --git a/src/Graphics/Vty/Attributes.hs b/src/Graphics/Vty/Attributes.hs
--- a/src/Graphics/Vty/Attributes.hs
+++ b/src/Graphics/Vty/Attributes.hs
@@ -1,6 +1,12 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE RankNTypes #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 -- | Display attributes
 --
 -- Typically the values 'defAttr' or 'currentAttr' are modified to form attributes:
@@ -33,11 +39,14 @@
 
 import Data.Bits
 import Data.Default
-import Data.Monoid
 import Data.Word
 
 import Graphics.Vty.Attributes.Color
 import Graphics.Vty.Attributes.Color240
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid
+#endif
 
 -- | A display attribute defines the Color and Style of all the characters rendered after the
 -- attribute is applied.
diff --git a/src/Graphics/Vty/DisplayAttributes.hs b/src/Graphics/Vty/DisplayAttributes.hs
--- a/src/Graphics/Vty/DisplayAttributes.hs
+++ b/src/Graphics/Vty/DisplayAttributes.hs
@@ -1,12 +1,21 @@
 -- Copyright 2009-2010 Corey O'Connor
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 module Graphics.Vty.DisplayAttributes
     where
 
 import Graphics.Vty.Attributes
 
 import Data.Bits ((.&.))
+
+#if !(MIN_VERSION_base(4,8,0))
 import Data.Monoid (Monoid(..), mconcat)
+#endif
 
 -- | Given the previously applied display attributes as a FixedAttr and the current display
 -- attributes as an Attr produces a FixedAttr that represents the current display attributes. This
diff --git a/src/Graphics/Vty/Image/Internal.hs b/src/Graphics/Vty/Image/Internal.hs
--- a/src/Graphics/Vty/Image/Internal.hs
+++ b/src/Graphics/Vty/Image/Internal.hs
@@ -1,5 +1,11 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# OPTIONS_HADDOCK hide #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 module Graphics.Vty.Image.Internal where
 
 import Graphics.Vty.Attributes
@@ -7,8 +13,11 @@
 
 import Control.DeepSeq
 
-import Data.Monoid
 import qualified Data.Text.Lazy as TL
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid
+#endif
 
 -- | A display text is a Data.Text.Lazy
 --
diff --git a/src/Graphics/Vty/Inline.hs b/src/Graphics/Vty/Inline.hs
--- a/src/Graphics/Vty/Inline.hs
+++ b/src/Graphics/Vty/Inline.hs
@@ -24,7 +24,13 @@
 -- 'putAttrChange'
 --
 -- Copyright 2009-2010 Corey O'Connor
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 module Graphics.Vty.Inline ( module Graphics.Vty.Inline
                            , withVty
                            )
@@ -37,14 +43,17 @@
 
 import Blaze.ByteString.Builder (writeToByteString)
 
-import Control.Applicative
 import Control.Monad.State.Strict
 
 import Data.Bits ( (.&.), complement )
 import Data.IORef
-import Data.Monoid ( mappend )
 
 import System.IO
+
+#if !(MIN_VERSION_base(4,8,0))
+import Control.Applicative
+import Data.Monoid ( mappend )
+#endif
 
 type InlineM v = State Attr v
 
diff --git a/src/Graphics/Vty/Inline/Unsafe.hs b/src/Graphics/Vty/Inline/Unsafe.hs
--- a/src/Graphics/Vty/Inline/Unsafe.hs
+++ b/src/Graphics/Vty/Inline/Unsafe.hs
@@ -1,11 +1,14 @@
 {-# LANGUAGE CPP #-}
 {-# OPTIONS_HADDOCK hide #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 module Graphics.Vty.Inline.Unsafe where
 
 import Graphics.Vty
 
-import Control.Applicative
-
 import Data.Default
 import Data.Monoid
 import Data.IORef
@@ -17,6 +20,10 @@
 import System.IO.Unsafe
 
 import System.Posix.IO (handleToFd)
+
+#if !(MIN_VERSION_base(4,8,0))
+import Control.Applicative
+#endif
 
 globalVty :: IORef (Maybe Vty)
 {-# NOINLINE globalVty #-}
diff --git a/src/Graphics/Vty/Input.hs b/src/Graphics/Vty/Input.hs
--- a/src/Graphics/Vty/Input.hs
+++ b/src/Graphics/Vty/Input.hs
@@ -1,4 +1,10 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE RecordWildCards #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 -- | The input layer for VTY. This provides methods for initializing an 'Input' structure which can
 -- then be used to read 'Event's from the terminal.
 --
@@ -133,11 +139,13 @@
 import Control.Concurrent
 import Control.Lens
 
-import Data.Functor ((<$>))
-import Data.Monoid
-
 import qualified System.Console.Terminfo as Terminfo
 import System.Posix.Signals.Exts
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Functor ((<$>))
+import Data.Monoid
+#endif
 
 -- | Set up the terminal with file descriptor `inputFd` for input.  Returns a 'Input'.
 --
diff --git a/src/Graphics/Vty/Input/Classify.hs b/src/Graphics/Vty/Input/Classify.hs
--- a/src/Graphics/Vty/Input/Classify.hs
+++ b/src/Graphics/Vty/Input/Classify.hs
@@ -60,14 +60,21 @@
 classify table =
     let standardClassifier = compile table
     in \s -> case s of
-        (c:_) | ord c >= 0xC2 && utf8Length (ord c) > length s -> Prefix -- beginning of an utf8 sequence
-        (c:_) | ord c >= 0xC2 -> classifyUtf8 s -- As soon as
-        _ -> standardClassifier s
+        c:cs | ord c >= 0xC2 -> classifyUtf8 c cs
+        _                    -> standardClassifier s
 
-classifyUtf8 :: [Char] -> KClass
-classifyUtf8 s = case decode ((map (fromIntegral . ord) s) :: [Word8]) of
-    Just (unicodeChar, _) -> Valid (EvKey (KChar unicodeChar) []) []
-    _ -> Invalid -- something bad happened; just ignore and continue.
+classifyUtf8 :: Char -> [Char] -> KClass
+classifyUtf8 c cs =
+  let n = utf8Length (ord c)
+      (codepoint,rest) = splitAt n (c:cs)
+
+      codepoint8 :: [Word8]
+      codepoint8 = map (fromIntegral . ord) codepoint
+
+  in case decode codepoint8 of
+       _ | n < length codepoint -> Prefix
+       Just (unicodeChar, _)    -> Valid (EvKey (KChar unicodeChar) []) rest
+       Nothing                  -> Invalid -- something bad happened; just ignore and continue.
 
 utf8Length :: (Num t, Ord a, Num a) => a -> t
 utf8Length c
diff --git a/src/Graphics/Vty/Output.hs b/src/Graphics/Vty/Output.hs
--- a/src/Graphics/Vty/Output.hs
+++ b/src/Graphics/Vty/Output.hs
@@ -1,5 +1,11 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE NamedFieldPuns #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 --  | Output interface.
 --
 --  Access to the current terminal or a specific terminal device.
@@ -40,10 +46,11 @@
 
 import Control.Monad.Trans
 
-import Data.Monoid (mappend)
 import Data.List (isPrefixOf)
 
-import System.Posix.Env (getEnv)
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid (mappend)
+#endif
 
 -- | Returns a `Output` for the terminal specified in `Config`
 --
diff --git a/src/Graphics/Vty/Output/Interface.hs b/src/Graphics/Vty/Output/Interface.hs
--- a/src/Graphics/Vty/Output/Interface.hs
+++ b/src/Graphics/Vty/Output/Interface.hs
@@ -1,10 +1,16 @@
 -- Copyright Corey O'Connor
 -- General philosophy is: MonadIO is for equations exposed to clients.
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE FlexibleContexts #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 module Graphics.Vty.Output.Interface
 where
 
@@ -23,15 +29,18 @@
 
 import qualified Data.ByteString as BS
 import Data.IORef
-import Data.Monoid (mempty, mappend)
 import qualified Data.Text.Encoding as T
 import qualified Data.Text.Lazy as TL
 import qualified Data.Vector as Vector
 
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid (mempty, mappend)
+#endif
+
 data Output = Output
     { -- | Text identifier for the output device. Used for debugging. 
       terminalID :: String
-    , releaseTerminal :: MonadIO m => m ()
+    , releaseTerminal :: forall m. MonadIO m => m ()
     -- | Clear the display and initialize the terminal to some initial display state. 
     --
     -- The expectation of a program is that the display starts in some initial state. 
@@ -46,12 +55,12 @@
     --
     --  - The previous state cannot be determined
     --  - When exclusive access to a display is released the display returns to the previous state.
-    , reserveDisplay :: MonadIO m => m ()
+    , reserveDisplay :: forall m. MonadIO m => m ()
     -- | Return the display to the state before `reserveDisplay`
     -- If no previous state then set the display state to the initial state.
-    , releaseDisplay :: MonadIO m => m ()
+    , releaseDisplay :: forall m. MonadIO m => m ()
     -- | Returns the current display bounds.
-    , displayBounds :: MonadIO m => m DisplayRegion
+    , displayBounds :: forall m. MonadIO m => m DisplayRegion
     -- | Output the byte string to the terminal device.
     , outputByteBuffer :: BS.ByteString -> IO ()
     -- | Maximum number of colors supported by the context.
@@ -62,7 +71,7 @@
     -- | Acquire display access to the given region of the display.
     -- Currently all regions have the upper left corner of (0,0) and the lower right corner at 
     -- (max displayWidth providedWidth, max displayHeight providedHeight)
-    , mkDisplayContext :: MonadIO m => Output -> DisplayRegion -> m DisplayContext
+    , mkDisplayContext :: forall m. MonadIO m => Output -> DisplayRegion -> m DisplayContext
     }
 
 displayContext :: MonadIO m => Output -> DisplayRegion -> m DisplayContext
diff --git a/src/Graphics/Vty/Output/TerminfoBased.hs b/src/Graphics/Vty/Output/TerminfoBased.hs
--- a/src/Graphics/Vty/Output/TerminfoBased.hs
+++ b/src/Graphics/Vty/Output/TerminfoBased.hs
@@ -3,6 +3,11 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# OPTIONS_GHC -D_XOPEN_SOURCE=500 -fno-warn-warnings-deprecations #-}
 {-# CFILES gwinsz.c #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 -- |  Terminfo based terminal handling.
 --
 -- The color handling assumes tektronix like. No HP support provided. If the terminal is not one I
@@ -28,10 +33,8 @@
 import Control.Monad.Trans
 
 import Data.Bits ((.&.))
-import Data.Foldable (foldMap)
 import Data.IORef
 import Data.Maybe (isJust, isNothing, fromJust)
-import Data.Monoid
 import Data.Word
 
 import Foreign.C.Types ( CInt(..), CLong(..) )
@@ -41,6 +44,11 @@
 import qualified System.Console.Terminfo as Terminfo
 import System.Posix.IO (fdWriteBuf)
 import System.Posix.Types (Fd(..))
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Foldable (foldMap)
+import Data.Monoid
+#endif
 
 data TerminfoCaps = TerminfoCaps 
     { smcup :: Maybe CapExpression
diff --git a/src/Graphics/Vty/Output/XTermColor.hs b/src/Graphics/Vty/Output/XTermColor.hs
--- a/src/Graphics/Vty/Output/XTermColor.hs
+++ b/src/Graphics/Vty/Output/XTermColor.hs
@@ -1,3 +1,9 @@
+{-# LANGUAGE CPP #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 -- Copyright 2009-2010 Corey O'Connor
 module Graphics.Vty.Output.XTermColor ( reserveTerminal )
     where
@@ -8,14 +14,16 @@
 import Blaze.ByteString.Builder (writeToByteString)
 import Blaze.ByteString.Builder.Word (writeWord8)
 
-import Control.Applicative
 import Control.Monad (void)
 import Control.Monad.Trans
 
-import Data.Foldable (foldMap)
-
 import System.Posix.IO (fdWrite)
 import System.Posix.Types (Fd)
+
+#if !(MIN_VERSION_base(4,8,0))
+import Control.Applicative
+import Data.Foldable (foldMap)
+#endif
 
 -- | Initialize the display to UTF-8. 
 reserveTerminal :: ( Applicative m, MonadIO m ) => String -> Fd -> m Output
diff --git a/src/Graphics/Vty/PictureToSpans.hs b/src/Graphics/Vty/PictureToSpans.hs
--- a/src/Graphics/Vty/PictureToSpans.hs
+++ b/src/Graphics/Vty/PictureToSpans.hs
@@ -5,6 +5,11 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TemplateHaskell #-}
+
+#ifndef MIN_VERSION_base
+#defined MIN_VERSION_base(x,y,z) 1
+#endif
+
 {- | Transforms an image into rows of operations.
  -}
 module Graphics.Vty.PictureToSpans where
@@ -27,11 +32,14 @@
 #endif
 
 import qualified Data.Vector as Vector hiding ( take, replicate )
-import Data.Monoid (mappend)
 import Data.Vector.Mutable ( MVector(..))
 import qualified Data.Vector.Mutable as MVector
 
 import qualified Data.Text.Lazy as TL
+
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid (mappend)
+#endif
 
 type MRowOps s = MVector s SpanOps
 
diff --git a/vty.cabal b/vty.cabal
--- a/vty.cabal
+++ b/vty.cabal
@@ -1,5 +1,5 @@
 name:                vty
-version:             5.2.10
+version:             5.2.11
 license:             BSD3
 license-file:        LICENSE
 author:              AUTHORS
@@ -142,7 +142,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -174,7 +174,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        terminfo >= 0.3 && < 0.5,
@@ -208,7 +208,7 @@
                        bytestring,
                        containers,
                        data-default >= 0.5.3,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        terminfo >= 0.3 && < 0.5,
                        text >= 0.11.3,
@@ -241,7 +241,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -267,7 +267,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -295,7 +295,7 @@
                        blaze-builder >= 0.3.3.2 && < 0.5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        terminfo >= 0.3 && < 0.5,
                        text >= 0.11.3,
@@ -324,7 +324,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -352,7 +352,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -379,7 +379,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -407,7 +407,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        terminfo >= 0.3 && < 0.5,
                        text >= 0.11.3,
@@ -439,7 +439,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -471,7 +471,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -503,7 +503,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -529,7 +529,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        mtl >= 1.1.1.0 && < 2.3,
                        text >= 0.11.3,
                        unix,
@@ -558,7 +558,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        lens >= 3.9.0.2 && < 5.0,
                        mtl >= 1.1.1.0 && < 2.3,
                        terminfo >= 0.3 && < 0.5,
@@ -593,7 +593,7 @@
                        base >= 4 && < 5,
                        bytestring,
                        containers,
-                       deepseq >= 1.1 && < 1.4,
+                       deepseq >= 1.1 && < 1.5,
                        lens >= 3.9.0.2 && < 5.0,
                        mtl >= 1.1.1.0 && < 2.3,
                        string-qq,