diff --git a/src/Wumpus/Tree/Draw.hs b/src/Wumpus/Tree/Draw.hs
--- a/src/Wumpus/Tree/Draw.hs
+++ b/src/Wumpus/Tree/Draw.hs
@@ -29,7 +29,6 @@
 import Wumpus.Basic.Dots.AnchorDots
 import Wumpus.Basic.Graphic   
 
-import Data.VectorSpace                         -- package: vector-space
 
 import Control.Monad
 import Data.Tree hiding ( drawTree )
@@ -39,20 +38,20 @@
 ---------------------------------------------------------------------------------
 -- Draw individual connector between parent and each child node.
 
-drawTree :: (Real u, Floating u, FromPtSize u, InnerSpace (Vec2 u)) 
+drawTree :: (Real u, Floating u, FromPtSize u) 
          => (a -> TreeNode u) 
          -> CoordTree u a 
          -> Drawing u
 drawTree drawF tree = drawTracing $ drawTop drawF tree 
 
 
-drawTop :: (Real u, Floating u, InnerSpace (Vec2 u)) 
+drawTop :: (Real u, Floating u) 
         => (a -> TreeNode u) -> CoordTree u a -> TraceDrawing u ()
 drawTop fn (Node (pt,a) ns) = do 
     ancr <- drawi $ fn a `at` pt
     mapM_ (draw1 fn ancr) ns
 
-draw1 :: (Real u, Floating u, InnerSpace (Vec2 u))  
+draw1 :: (Real u, Floating u)
       => (a -> TreeNode u) 
       -> DotAnchor u 
       -> CoordTree u a 
@@ -63,7 +62,7 @@
     mapM_ (draw1 fn ancr) ns   
 
 
-connector :: (Real u, Floating u, InnerSpace (Vec2 u)) 
+connector :: (Real u, Floating u) 
           => DotAnchor u -> DotAnchor u -> Graphic u
 connector a1 a2 = openStroke $ vertexPath [p1,p2]
   where  
@@ -74,7 +73,7 @@
 
 
 
-anchorAngles :: (Floating u, Real u, InnerSpace (Vec2 u)) 
+anchorAngles :: (Floating u, Real u) 
              => Point2 u -> Point2 u -> (Radian,Radian)
 anchorAngles f t = (theta0, theta1)
   where
diff --git a/src/Wumpus/Tree/VersionNumber.hs b/src/Wumpus/Tree/VersionNumber.hs
--- a/src/Wumpus/Tree/VersionNumber.hs
+++ b/src/Wumpus/Tree/VersionNumber.hs
@@ -22,7 +22,7 @@
 
 -- | Version number
 --
--- > (0,11,0)
+-- > (0,11,1)
 --
 wumpus_tree_version :: (Int,Int,Int)
-wumpus_tree_version = (0,11,0)
+wumpus_tree_version = (0,11,1)
diff --git a/wumpus-tree.cabal b/wumpus-tree.cabal
--- a/wumpus-tree.cabal
+++ b/wumpus-tree.cabal
@@ -1,5 +1,5 @@
 name:             wumpus-tree
-version:          0.11.0
+version:          0.11.1
 license:          BSD3
 license-file:     LICENSE
 copyright:        Stephen Tetley <stephen.tetley@gmail.com>
@@ -32,6 +32,11 @@
   .
   Changelog:
   .
+  0.11.0 to 0.11.1:
+  .
+  * Removed unused @InnerSpace@ constriant on functions in 
+    @Wumpus.Tree.Draw@.
+  .
   0.10.0 to 0.11.0:
   .
   * Changed types of drawing functions so they can be run with 
@@ -72,7 +77,7 @@
 library
   hs-source-dirs:     src
   build-depends:      base              <  5, 
-                      containers        >= 0.3.0     && < 0.4.0,
+                      containers        >= 0.3.0     && < 0.6.0,
                       vector-space      >= 0.6,
                       wumpus-core       == 0.40.0,
                       wumpus-basic      == 0.13.0