diff --git a/CHANGELOG b/CHANGELOG
new file mode 100644
--- /dev/null
+++ b/CHANGELOG
@@ -0,0 +1,19 @@
+0.3.4 (2018-05-28)
+ * #29: Add Semigroup instances (needed for GHC 8.4)
+ * Add NfData instances
+
+0.3.3 (2016-05-30)
+ * Document precondition of occurrence > 0 on from*List functions.
+ * #18: Compatibility with GHC 8.0
+ * #13: Fix warnings about redundant imports
+ * #22: Fixed warnings about unnecessary constraints
+
+0.3.2: (2016-01-12)
+ * #7: Work around doctest issue of ambiguous modules
+
+0.3.1: (2016-01-11)
+ * #4: Fix maxView to use deleteFindMax instead of deleteFindMin
+
+0.3.0: (2015-06-29)
+ * #3: Return Maybe instead of `fail`-ing in a monad 
+
diff --git a/Data/IntMultiSet.hs b/Data/IntMultiSet.hs
--- a/Data/IntMultiSet.hs
+++ b/Data/IntMultiSet.hs
@@ -14,17 +14,17 @@
 -- Stability   :  provisional
 -- Portability :  portable
 --
--- An efficient implementation of multisets of integers, also somtimes called bags.
+-- An efficient implementation of multisets of integers, also sometimes called bags.
 --
 -- A multiset is like a set, but it can contain multiple copies of the same element.
 --
 -- Since many function names (but not the type name) clash with
 -- "Prelude" names, this module is usually imported @qualified@, e.g.
 --
--- >  import Data.MultiSet (MultiSet)
--- >  import qualified Data.MultiSet as MultiSet
+-- >  import Data.IntMultiSet (IntMultiSet)
+-- >  import qualified Data.IntMultiSet as IntMultiSet
 --
--- The implementation of 'MultiSet' is based on the "Data.IntMap" module.
+-- The implementation of 'IntMultiSet' is based on the "Data.IntMap" module.
 --
 -- Many operations have a worst-case complexity of /O(min(n,W))/.
 -- This means that the operation can become linear in the number of
@@ -137,6 +137,10 @@
 #if __GLASGOW_HASKELL__ < 710
 import Data.Monoid (Monoid(..))
 #endif
+#if MIN_VERSION_base(4,11,0)
+import qualified Data.List.NonEmpty (toList)
+import Data.Semigroup (Semigroup(..), stimesIdempotentMonoid)
+#endif
 import Data.Typeable ()
 import Data.IntMap.Strict (IntMap)
 import Data.IntSet (IntSet)
@@ -145,6 +149,7 @@
 import qualified Data.IntSet as Set
 import qualified Data.List as List
 import qualified Data.MultiSet as MultiSet
+import Control.DeepSeq (NFData(..))
 
 {-
 -- just for testing
@@ -153,7 +158,9 @@
 import qualified List
 -}
 
+#if __GLASGOW_HASKELL__ < 800
 import Data.Typeable
+#endif
 #if __GLASGOW_HASKELL__
 import Text.Read
 import Data.Data (Data(..), mkNoRepType)
@@ -187,6 +194,16 @@
     mempty  = empty
     mappend = union
     mconcat = unions
+
+#if MIN_VERSION_base(4,11,0)
+instance Semigroup IntMultiSet where
+    (<>) = union
+    sconcat = unions . Data.List.NonEmpty.toList
+    stimes = stimesIdempotentMonoid
+#endif
+
+instance NFData IntMultiSet where
+    rnf = rnf . unMS
 
 #if __GLASGOW_HASKELL__
 
diff --git a/Data/MultiSet.hs b/Data/MultiSet.hs
--- a/Data/MultiSet.hs
+++ b/Data/MultiSet.hs
@@ -14,7 +14,7 @@
 -- Stability   :  provisional
 -- Portability :  portable
 --
--- An efficient implementation of multisets, also somtimes called bags.
+-- An efficient implementation of multisets, also sometimes called bags.
 --
 -- A multiset is like a set, but it can contain multiple copies of the same element.
 -- Unless otherwise specified all insert and remove opertions affect only a single copy of an element.
@@ -143,6 +143,10 @@
 #if __GLASGOW_HASKELL__ < 710
 import Data.Monoid (Monoid(..))
 #endif
+#if MIN_VERSION_base(4,11,0)
+import qualified Data.List.NonEmpty (toList)
+import Data.Semigroup (Semigroup(..), stimesIdempotentMonoid)
+#endif
 import Data.Typeable ()
 import qualified Data.Foldable as Foldable
 import Data.Map.Strict (Map)
@@ -150,6 +154,7 @@
 import qualified Data.Map.Strict as Map
 import qualified Data.Set as Set
 import qualified Data.List as List
+import Control.DeepSeq (NFData(..))
 
 {-
 -- just for testing
@@ -190,8 +195,18 @@
     mappend = union
     mconcat = unions
 
+#if MIN_VERSION_base(4,11,0)
+instance Ord a => Semigroup (MultiSet a) where
+    (<>) = union
+    sconcat = unions . Data.List.NonEmpty.toList
+    stimes = stimesIdempotentMonoid
+#endif
+
 instance Foldable.Foldable MultiSet where
     foldr = fold
+
+instance NFData a => NFData (MultiSet a) where
+    rnf = rnf . unMS
 
 #if __GLASGOW_HASKELL__
 
diff --git a/multiset.cabal b/multiset.cabal
--- a/multiset.cabal
+++ b/multiset.cabal
@@ -1,5 +1,5 @@
 name:             multiset
-version:          0.3.3
+version:          0.3.4
 author:           Twan van Laarhoven
 maintainer:       twanvl@gmail.com
 bug-reports:      https://github.com/twanvl/multiset/issues
@@ -12,7 +12,7 @@
 license-file:     LICENSE
 build-type:       Simple
 Cabal-version:    >= 1.10
-extra-source-files: include/Typeable.h
+extra-source-files: include/Typeable.h CHANGELOG
 
 source-repository head
     type:     git
@@ -25,7 +25,7 @@
   include-dirs:       include
   default-extensions: CPP
   ghc-options:        -Wall
-  build-depends:      containers >= 0.5, base >= 4 && < 5
+  build-depends:      containers >= 0.5, base >= 4 && < 5, deepseq >=1.2 && <1.5
 
 test-suite doctests
   default-language:   Haskell2010