diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+0.9.2.0:
+
+  Initial support for ghc 8.4. Updated to lts 10.8 in stack.yaml so
+  was able to drop extra intern dependency version. Now builds with
+  -Wcompat if ghc 8.0 or later is used.
+
 0.9.1.10:
 
   Updated the upper bound on time to work with ghc 8.2.1. Updated
diff --git a/src/Swish/GraphMem.hs b/src/Swish/GraphMem.hs
--- a/src/Swish/GraphMem.hs
+++ b/src/Swish/GraphMem.hs
@@ -8,7 +8,7 @@
 -- |
 --  Module      :  GraphMem
 --  Copyright   :  (c) 2003, Graham Klyne, 2009 Vasili I Galchin,
---                 2011, 2012, 2014, 2016 Douglas Burke
+--                 2011, 2012, 2014, 2016, 2018 Douglas Burke
 --  License     :  GPL V2
 --
 --  Maintainer  :  Douglas Burke
@@ -32,6 +32,8 @@
     , matchGraphMem
     ) where
 
+import qualified Data.Set as S
+
 import Swish.GraphClass
 import Swish.GraphMatch
 
@@ -41,7 +43,9 @@
 #endif
 import Data.Ord (comparing)
 
-import qualified Data.Set as S
+#if !(MIN_VERSION_base(4, 11, 0))
+import Data.Semigroup
+#endif
 
 -- | Simple memory-based graph type. 
 
@@ -61,9 +65,14 @@
 instance (Label lb) => Show (GraphMem lb) where
     show = graphShow
 
+instance (Label lb) => Semigroup (GraphMem lb) where
+    (<>) = addGraphs
+
 instance (Label lb) => Monoid (GraphMem lb) where
     mempty  = emptyGraph
-    mappend = addGraphs
+#if !(MIN_VERSION_base(4, 11, 0))
+    mappend = (<>)
+#endif
 
 graphShow   :: (Label lb) => GraphMem lb -> String
 graphShow g = "Graph:" ++ S.foldr ((++) . ("\n    " ++) . show) "" (arcs g)
diff --git a/src/Swish/RDF/Graph.hs b/src/Swish/RDF/Graph.hs
--- a/src/Swish/RDF/Graph.hs
+++ b/src/Swish/RDF/Graph.hs
@@ -9,7 +9,7 @@
 -- |
 --  Module      :  Graph
 --  Copyright   :  (c) 2003, Graham Klyne, 2009 Vasili I Galchin,
---                 2011, 2012, 2013, 2014, 2015, 2016 Douglas Burke
+--                 2011, 2012, 2013, 2014, 2015, 2016, 2018 Douglas Burke
 --  License     :  GPL V2
 --
 --  Maintainer  :  Douglas Burke
@@ -221,6 +221,10 @@
 import System.Locale (defaultTimeLocale)  
 #endif
 
+#if !(MIN_VERSION_base(4, 11, 0))
+import Data.Semigroup
+#endif
+
 import Text.Printf
 
 import qualified Data.Map as M
@@ -1283,10 +1287,17 @@
     getArcs      = statements 
     setArcs g as = g { statements=as }
 
--- | The 'mappend' operation uses 'merge' rather than 'addGraphs'.
+-- | The '<>' operation uses 'merge' rather than 'addGraphs'.
+instance (Label lb) => Semigroup (NSGraph lb) where
+    (<>) = merge
+
+-- | The 'mappend' operation uses the Semigroup instance
+--   (so 'merge' rather than 'addGraphs').
 instance (Label lb) => Monoid (NSGraph lb) where
     mempty  = emptyGraph
-    mappend = merge
+#if !(MIN_VERSION_base(4, 11, 0))
+    mappend = (<>)
+#endif
 
 -- fmapNSGraph :: (Ord lb1, Ord lb2) => (lb1 -> lb2) -> NSGraph lb1 -> NSGraph lb2
   
diff --git a/src/Swish/VarBinding.hs b/src/Swish/VarBinding.hs
--- a/src/Swish/VarBinding.hs
+++ b/src/Swish/VarBinding.hs
@@ -9,7 +9,7 @@
 -- |
 --  Module      :  VarBinding
 --  Copyright   :  (c) 2003, Graham Klyne, 2009 Vasili I Galchin, 
---                 2011, 2012, 2014, 2015, 2016 Douglas Burke
+--                 2011, 2012, 2014, 2015, 2016, 2018 Douglas Burke
 --  License     :  GPL V2
 --
 --  Maintainer  :  Douglas Burke
@@ -54,6 +54,10 @@
 import Data.Monoid (Monoid(..), mconcat)
 #endif
 
+#if !(MIN_VERSION_base(4, 11, 0))
+import Data.Semigroup
+#endif
+
 import Control.Monad (mplus)
 
 import Data.Function (on)
@@ -92,9 +96,14 @@
 
 -- | When combining instances, if there is an overlapping binding then
 --   the  value from the first instance is used.
+instance (Ord a, Ord b) => Semigroup (VarBinding a b) where
+    (<>) = joinVarBindings
+    
 instance (Ord a, Ord b) => Monoid (VarBinding a b) where
     mempty = nullVarBinding
-    mappend = joinVarBindings
+#if !(MIN_VERSION_base(4, 11, 0))
+    mappend = (<>)
+#endif
 
 -- | The Show instance only displays the pairs of variables
 --    in the binding.
@@ -102,7 +111,7 @@
 instance (Show a, Show b) => Show (VarBinding a b) where
     show = show . S.toList . vbEnum
 
--- | The null, or empry, binding maps no query variables.
+-- | The null, or empty, binding maps no query variables.
 --   This is the 'mempty' instance of the Monoid.
 --
 nullVarBinding :: VarBinding a b
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,6 +1,4 @@
 flags: {}
 packages:
 - '.'
-extra-deps:
-- intern-0.9.1.4
-resolver: lts-9.1
+resolver: lts-10.8
diff --git a/swish.cabal b/swish.cabal
--- a/swish.cabal
+++ b/swish.cabal
@@ -1,5 +1,5 @@
 Name:               swish
-Version:            0.9.1.10
+Version:            0.9.2.0
 Stability:          experimental
 License:            LGPL
 License-file:       LICENSE 
@@ -178,8 +178,12 @@
       Swish.Utils.ListHelpers
       Swish.VarBinding
 
-   ghc-options:
-      -Wall -fno-warn-orphans
+   if impl(ghc < 8.0.0)
+     ghc-options:
+        -Wall -fno-warn-orphans
+   if impl(ghc >= 8.0.0)
+     ghc-options:
+        -Wall -Wcompat -fno-warn-orphans
 
    -- if flag(developer)
    --    ghc-options: -Werror