diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Changes in 0.8.4.1
+
+  * All fields of LogDinD are strict and unpacked. This fixes NFData
+    instance and improves performance
+
+
 Changes in 0.8.4.0
 
   * Missing instances for CutDirection added
diff --git a/Data/Histogram/Bin/LogBinD.hs b/Data/Histogram/Bin/LogBinD.hs
--- a/Data/Histogram/Bin/LogBinD.hs
+++ b/Data/Histogram/Bin/LogBinD.hs
@@ -23,9 +23,9 @@
 --
 -- > b = logBinDN (lowerLimit b) (logBinDIncrement b) (nBins b)
 data LogBinD = LogBinD
-               Double -- Low border
-               Double -- Increment ratio
-               Int    -- Number of bins
+               {-# UNPACK #-} !Double -- Low border
+               {-# UNPACK #-} !Double -- Increment ratio
+               {-# UNPACK #-} !Int    -- Number of bins
                deriving (Eq,Data,Typeable)
 
 -- | Increment ratio for 'LogBinD'
diff --git a/histogram-fill.cabal b/histogram-fill.cabal
--- a/histogram-fill.cabal
+++ b/histogram-fill.cabal
@@ -1,5 +1,5 @@
 Name:           histogram-fill
-Version:        0.8.4.0
+Version:        0.8.4.1
 Synopsis:       Library for histograms creation.
 Description:
   This is library for histograms filling. Its aim to provide