diff --git a/log-domain.cabal b/log-domain.cabal
--- a/log-domain.cabal
+++ b/log-domain.cabal
@@ -1,6 +1,6 @@
 name:          log-domain
 category:      Numeric
-version:       0.3.0.1
+version:       0.4
 license:       BSD3
 cabal-version: >= 1.8
 license-file:  LICENSE
@@ -48,6 +48,7 @@
     deepseq                   >= 1.3      && < 1.5,
     distributive              >= 0.3      && < 1,
     generic-deriving          == 1.4.*,
+    hash                      >= 0.1.1    && < 1,
     hashable                  >= 1.1.2.3  && < 1.3,
     semigroupoids             >= 3.0.2    && < 4,
     semigroups                >= 0.8.4    && < 1,
diff --git a/src/Numeric/Log.hs b/src/Numeric/Log.hs
--- a/src/Numeric/Log.hs
+++ b/src/Numeric/Log.hs
@@ -30,6 +30,7 @@
 import Data.Functor.Bind
 import Data.Functor.Extend
 import Data.Hashable
+import Data.Hashable.Extras
 import Data.Int
 import Data.List as List hiding (sum)
 import Data.Monoid
@@ -73,6 +74,8 @@
 instance Hashable a => Hashable (Log a) where
   hashWithSalt i (Log a) = hashWithSalt i a
   {-# INLINE hashWithSalt #-}
+
+instance Hashable1 Log
 
 instance Storable a => Storable (Log a) where
   sizeOf = sizeOf . runLog