diff --git a/Data/Graph/Analysis/Reporting.hs b/Data/Graph/Analysis/Reporting.hs
--- a/Data/Graph/Analysis/Reporting.hs
+++ b/Data/Graph/Analysis/Reporting.hs
@@ -31,6 +31,8 @@
 
 import Data.Graph.Inductive(Node)
 import Data.GraphViz
+import Data.GraphViz.Attributes.Complete(Attribute(Size), Point(..), createPoint)
+import Data.GraphViz.Exception
 
 import Data.Time(getZonedTime, zonedTimeToLocalTime, formatTime)
 import Control.Exception.Extensible(SomeException(..), tryJust)
@@ -240,7 +242,8 @@
 
 graphImage :: FilePath -> FilePath -> VisProperties -> DocGraph
               -> IO (Either DocInline Location)
-graphImage rDir gDir vp dg = liftM (either' Text (File . fixPath))
+graphImage rDir gDir vp dg = handle getErr
+                             . liftM (Right . File . fixPath)
                              $ addExtension (runGraphviz dot)
                                             (format vp)
                                             filename
@@ -249,6 +252,9 @@
     filename = rDir </> gDir </> imageFile dg
     fixPath = makeRelative rDir
 
+    getErr :: GraphvizException -> IO (Either DocInline Location)
+    getErr = return . Left. Text . show
+
 graphImage' :: FilePath -> FilePath -> VisProperties -> DocGraph
                -> IO DocInline
 graphImage' rDir gDir vp dg = liftM (either id f)
@@ -278,8 +284,3 @@
     where
       replace '.' = '-'
       replace c   = c
-
--- | Map either element of an 'Either'.
-either'                 :: (a -> c) -> (b -> d) -> Either a b -> Either c d
-either' fl _  (Left a)  = Left  $ fl a
-either' _  fr (Right b) = Right $ fr b
diff --git a/Data/Graph/Analysis/Reporting/Pandoc.hs b/Data/Graph/Analysis/Reporting/Pandoc.hs
--- a/Data/Graph/Analysis/Reporting/Pandoc.hs
+++ b/Data/Graph/Analysis/Reporting/Pandoc.hs
@@ -195,7 +195,7 @@
 
 -- | Html output doesn't show the author and date; use this to print it.
 htmlInfo         :: String -> String -> Block
-htmlInfo auth dt = RawHtml html
+htmlInfo auth dt = RawBlock "html" html
     where
       heading = "<h1>Document Information</h1>"
       html = unlines [heading, htmlize auth, htmlize dt]
diff --git a/Data/Graph/Analysis/Types.hs b/Data/Graph/Analysis/Types.hs
--- a/Data/Graph/Analysis/Types.hs
+++ b/Data/Graph/Analysis/Types.hs
@@ -50,6 +50,8 @@
 
 import qualified Data.Set as S
 import Data.Set(Set)
+import qualified Data.Text.Lazy as T
+import Data.Text.Lazy(Text)
 
 -- -----------------------------------------------------------------------------
 
@@ -211,15 +213,20 @@
 -- | A class used to define which types are valid for clusters.
 class (Ord c) => ClusterType c where
     -- | Create a label for visualisation purposes with the GraphViz
-    --   library.  Default is @'const' 'Nothing'@.
-    clustID :: c -> Maybe GraphID
-    clustID = const Nothing
+    --   library.
+    clustID :: c -> GraphID
 
 instance ClusterType Int where
-    clustID = Just . Int
+    clustID = Int
 
+instance ClusterType Double where
+    clustID = Dbl
+
+instance ClusterType Text where
+    clustID = Str
+
 instance ClusterType String where
-    clustID = Just . Str
+    clustID = clustID . T.pack
 
 -- | A generic cluster-label type.
 data GenCluster a = GC { clust :: Int
diff --git a/Data/Graph/Analysis/Utils.hs b/Data/Graph/Analysis/Utils.hs
--- a/Data/Graph/Analysis/Utils.hs
+++ b/Data/Graph/Analysis/Utils.hs
@@ -69,10 +69,10 @@
 import Data.Graph.Inductive.Graph
 import Data.GraphViz( dotizeGraph
                     , GraphvizParams(isDirected)
-                    , nonClusteredParams
-                    , Attribute(..)
-                    , Pos(..)
-                    , Point(..))
+                    , nonClusteredParams)
+import Data.GraphViz.Attributes.Complete( Attribute(..)
+                                        , Pos(..)
+                                        , Point(..))
 
 import Data.List(nub, nubBy, (\\), find, sort, sortBy, group, groupBy)
 import Data.Maybe(fromJust)
diff --git a/Data/Graph/Analysis/Visualisation.hs b/Data/Graph/Analysis/Visualisation.hs
--- a/Data/Graph/Analysis/Visualisation.hs
+++ b/Data/Graph/Analysis/Visualisation.hs
@@ -50,14 +50,14 @@
 -}
 
 -- | Convert the 'GraphData' into 'DotGraph' format.
-graphviz :: (Ord cl) => GraphvizParams nl el cl l
+graphviz :: (Ord cl) => GraphvizParams Node nl el cl l
             -> GraphData nl el -> DotGraph Node
 graphviz = setDir graphToDot
 
 -- | Convert the clustered 'GraphData' into 'DotGraph' format.
 --   Cluster the nodes based upon their 'ClusterLabel' clusters.
 graphvizClusters    :: (ClusterLabel nl)
-                       => GraphvizParams nl el (Cluster nl) (NodeLabel nl)
+                       => GraphvizParams Node nl el (Cluster nl) (NodeLabel nl)
                        -> GraphData nl el -> DotGraph Node
 graphvizClusters ps = graphviz params
   where
@@ -72,8 +72,8 @@
 assignCluster (n,a) = C (cluster a) $ N (n, nodeLabel a)
 
 -- | A cross between 'applyDirAlg' and 'setDirectedness'.
-setDir :: (GraphvizParams nl el cl l -> AGr nl el -> a)
-          -> GraphvizParams nl el cl l -> GraphData nl el -> a
+setDir :: (GraphvizParams Node nl el cl l -> AGr nl el -> a)
+          -> GraphvizParams Node nl el cl l -> GraphData nl el -> a
 setDir f params gd = f params' (graph gd)
   where
     params' = params { isDirected = directedData gd }
diff --git a/Graphalyze.cabal b/Graphalyze.cabal
--- a/Graphalyze.cabal
+++ b/Graphalyze.cabal
@@ -1,5 +1,5 @@
 Name:                Graphalyze
-Version:             0.11.0.0
+Version:             0.12.0.0
 Synopsis:            Graph-Theoretic Analysis library.
 Description:         A library to use graph theory to analyse the relationships
                         inherent in discrete data.
@@ -31,8 +31,9 @@
                          time,
                          bktrees >= 0.2 && <0.4,
                          fgl >= 5.4.2.3 && < 5.5,
-                         graphviz >= 2999.11.0.0 && < 2999.12.0.0,
-                         pandoc >= 1.5 && < 1.7
+                         graphviz == 2999.12.*,
+                         pandoc == 1.8.*,
+                         text
 
         Exposed-Modules:     Data.Graph.Analysis
                              Data.Graph.Analysis.Types