diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 0.5.0
+### Changed
+- Include version boundaries and other changes submitted by Emily Pillmore.
+
 ## 0.4.0
 ### Changed
 - Remove fragile ForeignPtr implementation in favor of just storing ByteStrings.
diff --git a/secp256k1-haskell.cabal b/secp256k1-haskell.cabal
--- a/secp256k1-haskell.cabal
+++ b/secp256k1-haskell.cabal
@@ -1,13 +1,11 @@
-cabal-version: 2.0
+cabal-version: 1.24
 
--- This file has been generated from package.yaml by hpack version 0.33.0.
+-- This file has been generated from package.yaml by hpack version 0.34.2.
 --
 -- see: https://github.com/sol/hpack
---
--- hash: 911c4f6cd260a60f86d8394bdda0aa90dc6cb66e94f5d2adf02a14f7b2d38047
 
 name:           secp256k1-haskell
-version:        0.4.0
+version:        0.5.0
 synopsis:       Bindings for secp256k1
 description:    Sign and verify signatures using the secp256k1 library.
 category:       Crypto
@@ -39,16 +37,16 @@
   pkgconfig-depends:
       libsecp256k1
   build-depends:
-      QuickCheck
-    , base >=4.8 && <5
-    , base16-bytestring
-    , bytestring
-    , cereal
-    , deepseq
-    , entropy
-    , hashable
-    , string-conversions
-    , unliftio
+      QuickCheck >=2.9.2 && <2.15
+    , base >=4.9 && <5
+    , base16-bytestring >=0.1.1.6 && <1.1
+    , bytestring >=0.10.8 && <0.11
+    , cereal >=0.5.4 && <0.6
+    , deepseq >=1.4.2 && <1.5
+    , entropy >=0.3.8 && <0.5
+    , hashable >=1.2.6 && <1.4
+    , string-conversions >=0.4 && <0.5
+    , unliftio-core >=0.1.0 && <0.3
   default-language: Haskell2010
 
 test-suite spec
@@ -63,19 +61,19 @@
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       HUnit
-    , QuickCheck
-    , base >=4.8 && <5
-    , base16-bytestring
-    , bytestring
-    , cereal
-    , deepseq
-    , entropy
-    , hashable
+    , QuickCheck >=2.9.2 && <2.15
+    , base >=4.9 && <5
+    , base16-bytestring >=0.1.1.6 && <1.1
+    , bytestring >=0.10.8 && <0.11
+    , cereal >=0.5.4 && <0.6
+    , deepseq >=1.4.2 && <1.5
+    , entropy >=0.3.8 && <0.5
+    , hashable >=1.2.6 && <1.4
     , hspec
     , monad-par
     , mtl
     , secp256k1-haskell
-    , string-conversions
-    , unliftio
+    , string-conversions >=0.4 && <0.5
+    , unliftio-core >=0.1.0 && <0.3
   default-language: Haskell2010
   build-tool-depends: hspec-discover:hspec-discover
diff --git a/src/Crypto/Secp256k1.hs b/src/Crypto/Secp256k1.hs
--- a/src/Crypto/Secp256k1.hs
+++ b/src/Crypto/Secp256k1.hs
@@ -116,8 +116,14 @@
     get = CompactSig <$> getByteString 64
 
 decodeHex :: ConvertibleStrings a ByteString => a -> Maybe ByteString
+#if MIN_VERSION_base16_bytestring(1,0,0)
+decodeHex str = case B16.decode $ cs str of
+  Right bs -> Just bs
+  Left _ -> Nothing
+#else
 decodeHex str = if BS.null r then Just bs else Nothing where
     (bs, r) = B16.decode $ cs str
+#endif
 
 instance Read PubKey where
     readPrec = do
diff --git a/src/Crypto/Secp256k1/Internal.hs b/src/Crypto/Secp256k1/Internal.hs
--- a/src/Crypto/Secp256k1/Internal.hs
+++ b/src/Crypto/Secp256k1/Internal.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-|
 Module      : Crypto.Secp256k1.Internal
 License     : UNLICENSE
@@ -61,7 +60,7 @@
 isSuccess :: Ret -> Bool
 isSuccess 0 = False
 isSuccess 1 = True
-isSuccess n = error $ "isSuccess expected 0 or 1 but got " <> show n
+isSuccess n = error $ "isSuccess expected 0 or 1 but got " ++ show n
 
 unsafeUseByteString :: ByteString -> ((Ptr a, CSize) -> IO b) -> IO b
 unsafeUseByteString bs f =