diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,8 @@
+0.9.3 [2020.09.30]
+------------------
+* Add `Hashable` instances for `InternedString`, `InternedByteString`,
+  `InternedText`, and `IntSet`.
+
 0.9.2
 -----
 * Add a `Semigroup IntSet` instance.
diff --git a/Data/Interned/IntSet.hs b/Data/Interned/IntSet.hs
--- a/Data/Interned/IntSet.hs
+++ b/Data/Interned/IntSet.hs
@@ -111,17 +111,21 @@
 
 import Prelude hiding (lookup,filter,foldr,foldl,null,map)
 import qualified Data.List as List
-import Data.Monoid (Monoid(..))
 import Data.Maybe (fromMaybe)
-#if MIN_VERSION_base(4,9,0) && !(MIN_VERSION_base(4,11,0))
-import Data.Semigroup (Semigroup(..))
-#endif
 import Data.Interned.Internal
 import Data.Bits
 import Data.Hashable
 import Text.Read
 import GHC.Exts ( Word(..), Int(..), shiftRL# )
 
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid (Monoid(..))
+#endif
+
+#if MIN_VERSION_base(4,9,0) && !(MIN_VERSION_base(4,11,0))
+import Data.Semigroup (Semigroup(..))
+#endif
+
 -- import Data.Typeable
 -- import Data.Data (Data(..), mkNoRepType)
 
@@ -855,6 +859,11 @@
   showsPrec p xs = showParen (p > 10) $
     showString "fromList " . shows (toList xs)
 
+{--------------------------------------------------------------------
+  Hashable
+--------------------------------------------------------------------}
+instance Hashable IntSet where
+  hashWithSalt s x = hashWithSalt s $ identity x
 
 {--------------------------------------------------------------------
   Read
diff --git a/Data/Interned/Internal.hs b/Data/Interned/Internal.hs
--- a/Data/Interned/Internal.hs
+++ b/Data/Interned/Internal.hs
@@ -2,6 +2,7 @@
            , FlexibleInstances
            , FlexibleContexts
            , BangPatterns
+           , CPP
            , GeneralizedNewtypeDeriving #-}
 
 module Data.Interned.Internal
@@ -20,7 +21,9 @@
 import Data.Hashable
 import Data.HashMap.Strict (HashMap)
 import Data.Foldable
+#if !(MIN_VERSION_base(4,8,0))
 import Data.Traversable
+#endif
 import qualified Data.HashMap.Strict as HashMap
 import Data.IORef
 import GHC.IO (unsafeDupablePerformIO, unsafePerformIO)
diff --git a/Data/Interned/Internal/ByteString.hs b/Data/Interned/Internal/ByteString.hs
--- a/Data/Interned/Internal/ByteString.hs
+++ b/Data/Interned/Internal/ByteString.hs
@@ -26,6 +26,9 @@
 instance Show InternedByteString where
   showsPrec d (InternedByteString _ b) = showsPrec d b
 
+instance Hashable InternedByteString where
+  hashWithSalt s (InternedByteString i _) = hashWithSalt s i
+
 instance Interned InternedByteString where
   type Uninterned InternedByteString = ByteString
   newtype Description InternedByteString = DBS ByteString deriving (Eq,Hashable)
diff --git a/Data/Interned/Internal/String.hs b/Data/Interned/Internal/String.hs
--- a/Data/Interned/Internal/String.hs
+++ b/Data/Interned/Internal/String.hs
@@ -25,6 +25,9 @@
 instance Show InternedString where
   showsPrec d (IS _ b) = showsPrec d b
 
+instance Hashable InternedString where
+  hashWithSalt s (IS i _) = hashWithSalt s i
+
 instance Interned InternedString where
   type Uninterned InternedString = String
   data Description InternedString = Cons {-# UNPACK #-} !Char String | Nil
diff --git a/Data/Interned/Internal/Text.hs b/Data/Interned/Internal/Text.hs
--- a/Data/Interned/Internal/Text.hs
+++ b/Data/Interned/Internal/Text.hs
@@ -25,6 +25,9 @@
 instance Show InternedText where
   showsPrec d (InternedText _ b) = showsPrec d b
 
+instance Hashable InternedText where
+  hashWithSalt s (InternedText i _) = hashWithSalt s i
+
 instance Interned InternedText where
   type Uninterned InternedText = Text
   newtype Description InternedText = DT Text deriving (Eq)
diff --git a/intern.cabal b/intern.cabal
--- a/intern.cabal
+++ b/intern.cabal
@@ -1,8 +1,8 @@
 name:          intern
 category:      Data, Data Structures
-version:       0.9.2
+version:       0.9.3
 license:       BSD3
-cabal-version: >= 1.6
+cabal-version: >= 1.10
 license-file:  LICENSE
 author:        Edward A. Kmett
 maintainer:    Edward A. Kmett <ekmett@gmail.com>
@@ -19,7 +19,10 @@
              , GHC == 7.10.3
              , GHC == 8.0.2
              , GHC == 8.2.2
-             , GHC == 8.4.1
+             , GHC == 8.4.4
+             , GHC == 8.6.5
+             , GHC == 8.8.3
+             , GHC == 8.10.1
 synopsis:      Efficient hash-consing for arbitrary data types
 description:   Efficient hash-consing for arbitrary data types.
 
@@ -34,7 +37,7 @@
     base                 >= 4     && < 5,
     bytestring           >= 0.9   && < 0.11,
     text                 >= 0.11  && < 1.3,
-    hashable             >= 1.1   && < 1.3,
+    hashable             >= 1.1   && < 1.4,
     unordered-containers >= 0.2.1 && < 0.3,
     array                >= 0.3   && < 0.6
 
@@ -50,3 +53,4 @@
     Data.Interned.Internal.Text
 
   ghc-options: -Wall
+  default-language: Haskell2010