diff --git a/amazonka-core.cabal b/amazonka-core.cabal
--- a/amazonka-core.cabal
+++ b/amazonka-core.cabal
@@ -1,5 +1,5 @@
 name:                  amazonka-core
-version:               1.4.0
+version:               1.4.1
 synopsis:              Core data types and functionality for Amazonka libraries.
 homepage:              https://github.com/brendanhay/amazonka
 bug-reports:           https://github.com/brendanhay/amazonka/issues
@@ -80,6 +80,7 @@
         , conduit              >= 1.1
         , conduit-extra        >= 1.1
         , cryptonite           >= 0.4
+        , deepseq              >= 1.4
         , exceptions           >= 0.6
         , hashable             >= 1.2
         , http-conduit         >= 2.1.4
diff --git a/src/Network/AWS/Data/Base64.hs b/src/Network/AWS/Data/Base64.hs
--- a/src/Network/AWS/Data/Base64.hs
+++ b/src/Network/AWS/Data/Base64.hs
@@ -15,6 +15,7 @@
     , _Base64
     ) where
 
+import           Control.DeepSeq
 import           Data.Aeson.Types
 import qualified Data.Attoparsec.Text        as AText
 import qualified Data.ByteArray.Encoding     as BA
@@ -38,6 +39,7 @@
     deriving (Eq, Read, Ord, Data, Typeable, Generic)
 
 instance Hashable Base64
+instance NFData   Base64
 
 _Base64 :: Iso' Base64 ByteString
 _Base64 = iso unBase64 Base64
diff --git a/src/Network/AWS/Data/List1.hs b/src/Network/AWS/Data/List1.hs
--- a/src/Network/AWS/Data/List1.hs
+++ b/src/Network/AWS/Data/List1.hs
@@ -16,6 +16,7 @@
 module Network.AWS.Data.List1 where
 
 import           Control.Applicative
+import           Control.DeepSeq
 import           Control.Monad
 import           Data.Aeson
 import           Data.Coerce
@@ -50,6 +51,8 @@
         , Typeable
         , Generic
         )
+
+instance NFData a => NFData (List1 a)
 
 _List1 :: (Coercible a b, Coercible b a) => Iso' (List1 a) (NonEmpty b)
 _List1 = iso (coerce . toNonEmpty) (List1 . coerce)
diff --git a/src/Network/AWS/Data/Log.hs b/src/Network/AWS/Data/Log.hs
--- a/src/Network/AWS/Data/Log.hs
+++ b/src/Network/AWS/Data/Log.hs
@@ -100,9 +100,8 @@
 
 instance ToLog RequestBody where
     build = \case
-        RequestBodyBuilder     n _ -> " <msger:"   <> build n <> ">"
+        RequestBodyBuilder     n _ -> " <builder:" <> build n <> ">"
         RequestBodyStream      n _ -> " <stream:"  <> build n <> ">"
-        RequestBodyStreamChunked _ -> " <chunked>"
 
         RequestBodyLBS lbs
             | n <= 4096            -> build lbs
@@ -115,6 +114,8 @@
             | otherwise            -> " <strict:" <> build n <> ">"
           where
             n = BS.length bs
+
+        _                          -> " <chunked>"
 
 instance ToLog HttpException where
     build x = "[HttpException] {\n" <> build (show x) <> "\n}"
diff --git a/src/Network/AWS/Data/Map.hs b/src/Network/AWS/Data/Map.hs
--- a/src/Network/AWS/Data/Map.hs
+++ b/src/Network/AWS/Data/Map.hs
@@ -23,6 +23,7 @@
     , toQueryMap
     ) where
 
+import           Control.DeepSeq
 import           Control.Applicative
 import           Data.Aeson
 import           Data.Bifunctor
@@ -70,6 +71,7 @@
 _Map = iso (coerce . toMap) (Map . coerce)
 
 instance (Hashable k, Hashable v) => Hashable (Map k v)
+instance (NFData k,   NFData   v) => NFData   (Map k v)
 
 instance (Hashable k, Eq k) => IsList (Map k v) where
    type Item (Map k v) = (k, v)
diff --git a/src/Network/AWS/Data/Numeric.hs b/src/Network/AWS/Data/Numeric.hs
--- a/src/Network/AWS/Data/Numeric.hs
+++ b/src/Network/AWS/Data/Numeric.hs
@@ -13,6 +13,7 @@
 --
 module Network.AWS.Data.Numeric where
 
+import           Control.DeepSeq
 import           Control.Monad
 import           Data.Aeson.Types
 import           Data.Data                   (Data, Typeable)
@@ -53,6 +54,9 @@
 
 instance Hashable Nat where
     hashWithSalt salt (Nat n) = hashWithSalt salt (toInteger n)
+
+instance NFData Nat where
+    rnf = rnf . toInteger . unNat
 
 instance FromJSON Nat where
     parseJSON = parseJSON >=> go
diff --git a/src/Network/AWS/Data/Sensitive.hs b/src/Network/AWS/Data/Sensitive.hs
--- a/src/Network/AWS/Data/Sensitive.hs
+++ b/src/Network/AWS/Data/Sensitive.hs
@@ -12,6 +12,7 @@
 --
 module Network.AWS.Data.Sensitive where
 
+import           Control.DeepSeq
 import           Data.Data                   (Data, Typeable)
 import           Data.Hashable
 import           Data.Monoid
@@ -49,6 +50,7 @@
     show = const "******"
 
 instance Hashable a => Hashable (Sensitive a)
+instance NFData   a => NFData   (Sensitive a)
 
 _Sensitive :: Iso' (Sensitive a) a
 _Sensitive = iso desensitise Sensitive
diff --git a/src/Network/AWS/Data/Time.hs b/src/Network/AWS/Data/Time.hs
--- a/src/Network/AWS/Data/Time.hs
+++ b/src/Network/AWS/Data/Time.hs
@@ -35,6 +35,7 @@
     ) where
 
 import           Control.Applicative
+import           Control.DeepSeq
 import           Data.Aeson
 import           Data.Attoparsec.Text        (Parser)
 import qualified Data.Attoparsec.Text        as AText
@@ -80,6 +81,8 @@
 deriving instance Ord  (Time a)
 deriving instance Read (Time a)
 deriving instance Show (Time a)
+
+instance NFData (Time a)
 
 instance Hashable (Time a) where
     hashWithSalt salt (Time (UTCTime (ModifiedJulianDay d) t)) =
diff --git a/src/Network/AWS/Prelude.hs b/src/Network/AWS/Prelude.hs
--- a/src/Network/AWS/Prelude.hs
+++ b/src/Network/AWS/Prelude.hs
@@ -13,6 +13,7 @@
 
 import           Control.Applicative         as Export (Applicative, pure)
 import           Control.Applicative         as Export ((<$>), (<*>), (<|>))
+import           Control.DeepSeq             as Export (NFData)
 import           Data.Data                   as Export (Data, Typeable)
 import           Data.Foldable               as Export (Foldable)
 import           Data.Hashable               as Export (Hashable)
diff --git a/src/Network/AWS/Sign/V4.hs b/src/Network/AWS/Sign/V4.hs
--- a/src/Network/AWS/Sign/V4.hs
+++ b/src/Network/AWS/Sign/V4.hs
@@ -30,7 +30,7 @@
 import           Network.AWS.Data.Headers
 import           Network.AWS.Data.Query
 import           Network.AWS.Data.Time
-import           Network.AWS.Lens            ((%~), (.~), (<>~))
+import           Network.AWS.Lens            ((%~), (<>~))
 import           Network.AWS.Request
 import           Network.AWS.Sign.V4.Base
 import           Network.AWS.Sign.V4.Chunked
diff --git a/src/Network/AWS/Types.hs b/src/Network/AWS/Types.hs
--- a/src/Network/AWS/Types.hs
+++ b/src/Network/AWS/Types.hs
@@ -122,6 +122,7 @@
 
 import           Control.Applicative
 import           Control.Concurrent           (ThreadId)
+import           Control.DeepSeq
 import           Control.Exception
 import           Control.Monad.IO.Class
 import           Control.Monad.Trans.Resource
@@ -572,6 +573,7 @@
       deriving (Eq, Ord, Read, Show, Data, Typeable, Generic)
 
 instance Hashable Region
+instance NFData   Region
 
 instance FromText Region where
     parser = takeLowerText >>= \case
@@ -631,6 +633,9 @@
         , ToByteString
         , ToText
         )
+
+instance Hashable Seconds
+instance NFData   Seconds
 
 instance ToLog Seconds where
     build s = build (seconds s) <> "s"