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:               1.3.3.1
+version:               1.3.4
 synopsis:              Core data types and functionality for Amazonka libraries.
 homepage:              https://github.com/brendanhay/amazonka
 bug-reports:           https://github.com/brendanhay/amazonka/issues
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
@@ -22,6 +22,7 @@
 import           Data.Data                   (Data, Typeable)
 import qualified Data.Text.Encoding          as Text
 import           GHC.Generics                (Generic)
+import           Network.AWS.Data.Body
 import           Network.AWS.Data.ByteString
 import           Network.AWS.Data.JSON
 import           Network.AWS.Data.Query
@@ -51,10 +52,12 @@
 instance ToByteString Base64 where
     toBS = BA.convertToBase BA.Base64 . unBase64
 
-instance Show     Base64 where show      = show . toBS
-instance ToText   Base64 where toText    = Text.decodeUtf8 . toBS
-instance ToQuery  Base64 where toQuery   = toQuery . toBS
-instance FromXML  Base64 where parseXML  = parseXMLText "Base64"
-instance ToXML    Base64 where toXML     = toXMLText
-instance FromJSON Base64 where parseJSON = parseJSONText "Base64"
-instance ToJSON   Base64 where toJSON    = toJSONText
+instance Show         Base64 where show      = show . toBS
+instance ToText       Base64 where toText    = Text.decodeUtf8 . toBS
+instance ToQuery      Base64 where toQuery   = toQuery . toBS
+instance FromXML      Base64 where parseXML  = parseXMLText "Base64"
+instance ToXML        Base64 where toXML     = toXMLText
+instance FromJSON     Base64 where parseJSON = parseJSONText "Base64"
+instance ToJSON       Base64 where toJSON    = toJSONText
+instance ToHashedBody Base64 where toHashed  = toHashed . toBS
+instance ToBody       Base64
diff --git a/src/Network/AWS/Data/Body.hs b/src/Network/AWS/Data/Body.hs
--- a/src/Network/AWS/Data/Body.hs
+++ b/src/Network/AWS/Data/Body.hs
@@ -212,6 +212,9 @@
 instance ToBody HashedBody  where toBody = Hashed
 instance ToBody ChunkedBody where toBody = Chunked
 
+instance ToHashedBody a => ToBody (Maybe a) where
+    toBody = Hashed . maybe (toHashed BS.empty) toHashed
+
 instance ToBody String
 instance ToBody LBS.ByteString
 instance ToBody ByteString