diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,4 +3,6 @@
 # v0.1.0.1
 Documentation fixes.
 # v0.1.0.2
-Build with ghc 7.8.4
+Build with ghc 7.8.4.
+# v0.1.1.0
+StepFunction is now an instance of Functor.
diff --git a/dist/build/mergeStub/mergeStub-tmp/mergeStub.hs b/dist/build/mergeStub/mergeStub-tmp/mergeStub.hs
new file mode 100644
--- /dev/null
+++ b/dist/build/mergeStub/mergeStub-tmp/mergeStub.hs
@@ -0,0 +1,5 @@
+module Main ( main ) where
+import Distribution.Simple.Test.LibV09 ( stubMain )
+import Merge ( tests )
+main :: IO ()
+main = stubMain tests
diff --git a/src/Data/StepFunction.hs b/src/Data/StepFunction.hs
--- a/src/Data/StepFunction.hs
+++ b/src/Data/StepFunction.hs
@@ -38,6 +38,9 @@
     , transitions :: [Transition x y] -- ^ The transitions. 
     } deriving (Eq,Show)
 
+instance Functor (StepFunction x) where
+  fmap f (StepFunction d ts) = StepFunction (f d) (map (fmap f) ts)
+
 instance (Ord x,Eq y) => Ord (Transition x y) where
   compare t1 t2 | x_val t1 < x_val t2                                              = LT
                 | x_val t1 > x_val t2                                              = GT
diff --git a/step-function.cabal b/step-function.cabal
--- a/step-function.cabal
+++ b/step-function.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                step-function
-version:             0.1.0.2
+version:             0.1.1.0
 synopsis:            Step functions, staircase functions or piecewise constant functions
 description:         
   Step functions, staircase functions or piecewise constant functions.
@@ -27,7 +27,7 @@
 source-repository this
   type:     git
   location: http://github.com/jonpetterbergman/step-function
-  tag:      v0.1.0.2
+  tag:      v0.1.1.0
 
 
 library