diff --git a/graphite.cabal b/graphite.cabal
--- a/graphite.cabal
+++ b/graphite.cabal
@@ -1,5 +1,5 @@
 name:                graphite
-version:             0.9.7.0
+version:             0.9.8.0
 synopsis:            Graphs and networks library
 description:         Represent, analyze and visualize graphs
 homepage:            https://github.com/alx741/graphite#readme
diff --git a/src/Data/Graph/Types.hs b/src/Data/Graph/Types.hs
--- a/src/Data/Graph/Types.hs
+++ b/src/Data/Graph/Types.hs
@@ -26,9 +26,11 @@
     , tripleAttribute
     ) where
 
-import Data.List    (foldl')
-import GHC.Float    (float2Double)
-import GHC.Generics (Generic)
+import Control.Applicative ((<*>))
+import Data.Functor        ((<$>))
+import Data.List           (foldl')
+import GHC.Float           (float2Double)
+import GHC.Generics        (Generic)
 
 import Control.DeepSeq
 import Data.Hashable