diff --git a/src/Tahoe/SDMF/Internal/Share.hs b/src/Tahoe/SDMF/Internal/Share.hs
index 9f2dba091c35e3dd31d444022771bda46540b699..392cdf44f22abcd9d6c29884e649d33614570f5d 100644
--- a/src/Tahoe/SDMF/Internal/Share.hs
+++ b/src/Tahoe/SDMF/Internal/Share.hs
@@ -32,7 +32,7 @@ data Share = Share
     , -- | The size of a single ciphertext segment.
       shareSegmentSize :: Word64
     , -- | The length of the original plaintext.
-      shareDataLength :: Word8
+      shareDataLength :: Word64
     , -- | The 2048 bit "verification" RSA key.
       shareVerificationKey :: RSA.PublicKey
     , -- | The RSA signature of