diff --git a/src/Tahoe/CHK/Share.hs b/src/Tahoe/CHK/Share.hs
index 972172152190b97861e8004e8d434747fc091ea8..f1a443b9c5cb97806113c66ecfb4fd9f1147abfb 100644
--- a/src/Tahoe/CHK/Share.hs
+++ b/src/Tahoe/CHK/Share.hs
@@ -83,6 +83,7 @@ import Tahoe.CHK.URIExtension (
 import Tahoe.Util (chunkedBy, toStrictByteString)
 import Text.Megaparsec (parse)
 
+-- | A byte string of encrypted data.
 type Crypttext = BS.ByteString
 
 -- | Structured representation of a single CHK share.