diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,14 @@
 # Revision history for compact
 
+## 0.2.0.0  -- 2020-04-13
+
+* Bounds bumps
+* Add magic number to serialisation encoding
+
+## 0.1.0.1  -- 2017-02-27
+
+* A bit of cleanup.
+
 ## 0.1.0.0  -- 2017-02-27
 
 * First version.
diff --git a/Data/Compact/Serialize.hs b/Data/Compact/Serialize.hs
--- a/Data/Compact/Serialize.hs
+++ b/Data/Compact/Serialize.hs
@@ -2,7 +2,6 @@
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE GADTs #-}
-{-# LANGUAGE ForeignFunctionInterface #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
@@ -14,7 +13,6 @@
 import Type.Reflection
 import Control.Monad
 import Data.Monoid
-import Data.IORef
 import Data.Word
 import System.IO
 
@@ -23,10 +21,7 @@
 import Foreign.Marshal.Alloc
 
 import qualified Data.Binary as B
-import qualified Data.ByteString as BS
-import qualified Data.ByteString.Unsafe as BSU
 import qualified Data.ByteString.Lazy as BSL
-import qualified Data.ByteString.Builder as BSB
 
 import GHC.Compact
 import GHC.Compact.Serialized
@@ -37,13 +32,21 @@
 -- ghc-compact does not have a binary dependency
 instance (Typeable a) => B.Binary (CompactFile a) where
     get = do
+        magic <- B.get
+        when (magic /= magicNumber) $
+            fail "Data.Compact.Serialized: bad magic number"
         SomeTypeRep tyrep <- B.get
         case tyrep `eqTypeRep` typeRep @a of
           Just HRefl -> CompactFile <$> getSerializedCompact
           Nothing -> fail $
             "Data.Compact.Serialized: expected " ++ show (typeRep @a) ++
             " but got " ++ show tyrep
-    put (CompactFile a) = B.put (typeRep @a) >> putSerializedCompact a
+    put (CompactFile a) = B.put magicNumber >> B.put (typeRep @a) >> putSerializedCompact a
+
+-- Serves as a very rudimentary integrity check.
+-- Chosen at random by roll of a 2^64-sided die; it was a sight to behold.
+magicNumber :: Word64
+magicNumber = 0x7c155e7a53f094f2
 
 putPtr :: Ptr a -> B.Put
 putPtr = B.put @Word64 . fromIntegral . ptrToWordPtr
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -18,8 +18,8 @@
 the region, you should see a speedup in your major GC runs.
 
 This package is currently highly experimental, but we hope it may be useful to
-some people.  It is GHC 8.2 only.  The bare-bones library that ships with GHC is
-ghc-compact.
+some people.  It is GHC 8.2 and later only.  The bare-bones library that ships
+with GHC is `ghc-compact`.
 
 ## Quick start
 
diff --git a/compact.cabal b/compact.cabal
--- a/compact.cabal
+++ b/compact.cabal
@@ -1,5 +1,5 @@
 name:                compact
-version:             0.1.0.1
+version:             0.2.0.0
 synopsis:            Non-GC'd, contiguous storage for immutable data structures
 description:
     This package provides user-facing APIs for working with
@@ -11,8 +11,8 @@
     released).
 
     This package is currently highly experimental, but we hope it may
-    be useful to some people.  It is GHC 8.2 only.  The bare-bones library
-    that ships with GHC is ghc-compact.
+    be useful to some people.  It is GHC 8.2 and later only.  
+    The bare-bones library that ships with GHC is @ghc-compact@.
 license:             BSD3
 license-file:        LICENSE
 author:              Edward Z. Yang, Ben Gamari
@@ -24,15 +24,24 @@
 extra-source-files:  ChangeLog.md
 cabal-version:       >=1.10
 extra-source-files:  README.md tests/sample1.hs tests/sample2.hs
+tested-with:         GHC==8.2.1, GHC==8.2.2,
+                     GHC==8.4.1, GHC==8.4.2, GHC==8.4.3, GHC==8.4.4,
+                     GHC==8.6.1, GHC==8.6.2, GHC==8.6.3, GHC==8.6.4, GHC==8.6.5,
+                     GHC==8.8.1, GHC==8.8.2, GHC==8.8.3,
+                     GHC==8.10.1
 
+source-repository head
+  type:                git
+  location:            https://github.com/ezyang/compact
+
 library
   exposed-modules:     Data.Compact
                        Data.Compact.Serialize
-  build-depends:       base       >= 4.10 && < 4.11,
+  build-depends:       base       >= 4.10 && < 4.15,
                        ghc-compact,
                        -- TODO: SomeTypeRep instance is in unreleased version
                        -- of binary that is bundled with GHC dev branch
-                       binary     >= 0.8.4.1 && < 0.9,
+                       binary     >= 0.8.4.1 && < 0.11,
                        bytestring >= 0.10 && < 0.11
   default-language:    Haskell2010