diff --git a/sdl2-cairo.cabal b/sdl2-cairo.cabal
--- a/sdl2-cairo.cabal
+++ b/sdl2-cairo.cabal
@@ -2,9 +2,8 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                sdl2-cairo
-version:             0.1.0.1
-synopsis:            Binding to render with Cairo on SDL textures
-                     and optional convenience drawing API.
+version:             0.1.0.2
+synopsis:            Render with Cairo on SDL textures. Includes optional convenience drawing API.
 description:         This small library provides convenience functions to draw
                      on SDL2 textures with Cairo. As Cairo is complicated, it also
                      provides a drawing API, which is heavily inspired by Processing and
@@ -25,7 +24,7 @@
   default-language:    Haskell2010
   exposed-modules:     SDL.Cairo, SDL.Cairo.Canvas, SDL.Cairo.Canvas.Interactive
   --other-modules:
-  build-depends:       base >=4.8 && <=5
+  build-depends:       base >=4.7 && <=5
                      , sdl2 >=2.0.0
                      , cairo >=0.13
                      , linear
diff --git a/src/SDL/Cairo/Canvas.hs b/src/SDL/Cairo/Canvas.hs
--- a/src/SDL/Cairo/Canvas.hs
+++ b/src/SDL/Cairo/Canvas.hs
@@ -66,6 +66,7 @@
   module Graphics.Rendering.Cairo
 ) where
 
+import Control.Applicative
 import Data.Monoid
 import Control.Monad.State
 import Data.Word (Word8)
@@ -292,7 +293,7 @@
 arc :: Dim -> Double -> Double -> Canvas ()
 arc (D x y w h) sa ea = drawShape $ do
   C.save
-  C.translate x y
+  C.translate (x+(w/2)) (y+(h/2))
   C.scale (w/2) (h/2)
   C.arc 0 0 1 sa ea
   C.restore
@@ -469,7 +470,9 @@
 
 -- |if color (csFG/csBG) is set, perform given render block
 ifColor :: (CanvasState -> Maybe Color) -> (Color -> Render ()) -> Canvas ()
-ifColor cf m = get >>= \cs -> forM_ (cf cs) $ \c -> renderCairo (m c)
+ifColor cf m = get >>= \cs -> case cf cs of
+                                Just c -> renderCairo (m c)
+                                Nothing -> return ()
 
 -- |convert from 256-value RGBA to Double representation, set color
 setColor :: Color -> Render ()