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).
 
+## 0.1.8
+### Added
+- Add missing `NFData` instances for some types.
+
 ## 0.1.7
 ### Added
 - Add `NFData` instances for all types.
diff --git a/secp256k1-haskell.cabal b/secp256k1-haskell.cabal
--- a/secp256k1-haskell.cabal
+++ b/secp256k1-haskell.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 31ccf270598fdfc8d03cf317d6f7312b095657c13da49213c81d488825c3fb6f
+-- hash: 89af02aeb2d034b30650caa8ac3da870deac12d246a8fa513ab1fdc3033461f5
 
 name:           secp256k1-haskell
-version:        0.1.7
+version:        0.1.8
 synopsis:       Bindings for secp256k1 library from Bitcoin Core
 description:    Sign and verify signatures using the very fast C secp256k1 library from Pieter Wuille. Has Haskell types and abstractions for keys and signatures.
 category:       Crypto
diff --git a/src/Crypto/Secp256k1.hs b/src/Crypto/Secp256k1.hs
--- a/src/Crypto/Secp256k1.hs
+++ b/src/Crypto/Secp256k1.hs
@@ -84,6 +84,7 @@
 import           Text.Read                 (Lexeme (String), lexP, parens,
                                             pfail, readPrec)
 
+import           Control.DeepSeq
 import           Crypto.Secp256k1.Internal
 
 newtype PubKey = PubKey (ForeignPtr PubKey64)
@@ -92,6 +93,24 @@
 newtype SecKey = SecKey (ForeignPtr SecKey32)
 newtype Tweak = Tweak (ForeignPtr Tweak32)
 newtype RecSig = RecSig (ForeignPtr RecSig65)
+
+instance NFData PubKey where
+    rnf (PubKey p) = p `seq` ()
+
+instance NFData Msg where
+    rnf (Msg p) = p `seq` ()
+
+instance NFData Sig where
+    rnf (Sig p) = p `seq` ()
+
+instance NFData SecKey where
+    rnf (SecKey p) = p `seq` ()
+
+instance NFData Tweak where
+    rnf (Tweak p) = p `seq` ()
+
+instance NFData RecSig where
+    rnf (RecSig p) = p `seq` ()
 
 decodeHex :: ConvertibleStrings a ByteString => a -> Maybe ByteString
 decodeHex str = if BS.null r then Just bs else Nothing where