diff --git a/pandoc-server.cabal b/pandoc-server.cabal
--- a/pandoc-server.cabal
+++ b/pandoc-server.cabal
@@ -1,6 +1,6 @@
 cabal-version:   2.4
 name:            pandoc-server
-version:         0.1.0.3
+version:         0.1.0.4
 build-type:      Simple
 license:         GPL-2.0-or-later
 license-file:    COPYING.md
@@ -54,7 +54,7 @@
                  containers            >= 0.6.0.1  && < 0.7,
                  aeson                 >= 2.0      && < 2.3,
                  bytestring            >= 0.9      && < 0.13,
-                 base64                >= 0.4      && < 0.5,
+                 base64-bytestring     >= 0.1      && < 1.3,
                  doctemplates          >= 0.11     && < 0.12,
                  data-default          >= 0.4      && < 0.8,
                  text                  >= 1.1.1.0  && < 2.2,
diff --git a/src/Text/Pandoc/Server.hs b/src/Text/Pandoc/Server.hs
--- a/src/Text/Pandoc/Server.hs
+++ b/src/Text/Pandoc/Server.hs
@@ -29,7 +29,7 @@
 import Data.Maybe (fromMaybe)
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Lazy as BL
-import Data.ByteString.Base64 (decodeBase64, encodeBase64)
+import qualified Data.ByteString.Base64 as Base64 (decodeLenient, encode)
 import Data.Default
 import Control.Monad (when, unless, foldM)
 import qualified Data.Set as Set
@@ -111,15 +111,11 @@
   deriving (Show, Eq)
 
 instance ToJSON Blob where
-  toJSON (Blob bs) = toJSON (encodeBase64 $ BL.toStrict bs)
+  toJSON (Blob bs) = toJSON (UTF8.toText . Base64.encode $ BL.toStrict bs)
 
 instance FromJSON Blob where
- parseJSON = withText "Blob" $ \t -> do
-   let inp = UTF8.fromText t
-   case decodeBase64 inp of
-        Right bs -> return $ Blob $ BL.fromStrict bs
-        Left _ -> -- treat as regular text
-                    return $ Blob $ BL.fromStrict inp
+ parseJSON = withText "Blob" $
+   pure . Blob . BL.fromStrict . Base64.decodeLenient . UTF8.fromText
 
 -- This is the data to be supplied by the JSON payload
 -- of requests.  Maybe values may be omitted and will be
@@ -236,7 +232,8 @@
   --    handleErr =<< liftIO (runIO (convert' params))
   -- will allow the IO operations.
   convertText params = handleErr $
-    runPure (convert' return (return . encodeBase64 . BL.toStrict) params)
+    runPure (convert' return (return . UTF8.toText .
+                               Base64.encode . BL.toStrict) params)
 
   convertBytes params = handleErr $
     runPure (convert' (return . UTF8.fromText) (return . BL.toStrict) params)
@@ -245,7 +242,7 @@
     runPure
       (convert'
         (\t -> Succeeded t False . map toMessage <$> getLog)
-        (\bs -> Succeeded (encodeBase64 (BL.toStrict bs)) True
+        (\bs -> Succeeded (UTF8.toText $ Base64.encode (BL.toStrict bs)) True
                  . map toMessage <$> getLog)
         params)
 
@@ -341,11 +338,9 @@
 
     let reader = case readerSpec of
                 TextReader r -> r readeropts
-                ByteStringReader r -> \t -> do
-                  let eitherbs = decodeBase64 $ UTF8.fromText t
-                  case eitherbs of
-                    Left errt -> throwError $ PandocSomeError errt
-                    Right bs -> r readeropts $ BL.fromStrict bs
+                ByteStringReader r ->
+                  r readeropts . BL.fromStrict . Base64.decodeLenient
+                    . UTF8.fromText
 
     let writer d@(Pandoc meta _) = do
           case lookupMetaString "lang" meta of