diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -4,3 +4,6 @@
 0.1.1.1:
 		added prob to Histogram, Histogram2D
 		changed return of getBins to curried form
+
+0.1.1.2:
+		fixed bug - not dividing by sum - prob for Histogram2D
diff --git a/hmatrix-gsl-stats.cabal b/hmatrix-gsl-stats.cabal
--- a/hmatrix-gsl-stats.cabal
+++ b/hmatrix-gsl-stats.cabal
@@ -1,5 +1,5 @@
 Name:               hmatrix-gsl-stats
-Version:            0.1.1.1
+Version:            0.1.1.2
 License:            GPL
 License-file:       LICENSE
 Copyright:          (c) A.V.H. McPhail 2010
diff --git a/lib/Numeric/GSL/Histogram2D.hs b/lib/Numeric/GSL/Histogram2D.hs
--- a/lib/Numeric/GSL/Histogram2D.hs
+++ b/lib/Numeric/GSL/Histogram2D.hs
@@ -40,7 +40,7 @@
 import Data.Packed.Matrix
 import Data.Packed.Development
 
---import Numeric.LinearAlgebra.Linear
+import Numeric.LinearAlgebra.Interface()
 
 --import Control.Monad
 --import Control.Monad(when)
@@ -322,10 +322,10 @@
 
 -- | find the probability of occuring for each element of the input vector
 prob :: Histogram2D -> (Vector Double,Vector Double) -> Vector Double
-prob (H _ _ h) (x,y) = unsafePerformIO $ do
+prob hi@(H _ _ h) (x,y) = unsafePerformIO $ do
                r <- createVector $ dim x
                app3 (\xs' x' ys' y' rs' r' -> withForeignPtr h $ \h' -> histogram2d_prob h' xs' x' ys' y' rs' r') vec x vec y vec r "histogram2d_prob"
-               return r
+               return $ r/(constant (sum hi) (dim x))
 
 foreign import ccall "histogram-aux.h hist2d_prob" histogram2d_prob :: Hist2DHandle -> CInt -> Ptr Double -> CInt -> Ptr Double -> CInt -> Ptr Double -> IO CInt