diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,9 @@
 # Changelog for Hedis
 
+## 0.14.1
+
+* PR #162. Improved documentation for EVALSHA
+
 ## 0.14.0
 
 * PR #157. Clustering support
diff --git a/hedis.cabal b/hedis.cabal
--- a/hedis.cabal
+++ b/hedis.cabal
@@ -1,5 +1,5 @@
 name:               hedis
-version:            0.14.0
+version:            0.14.1
 synopsis:
     Client library for the Redis datastore: supports full command set,
     pipelining.
diff --git a/src/Database/Redis/ManualCommands.hs b/src/Database/Redis/ManualCommands.hs
--- a/src/Database/Redis/ManualCommands.hs
+++ b/src/Database/Redis/ManualCommands.hs
@@ -360,9 +360,11 @@
   where
     numkeys = toInteger (length keys)
 
+-- | Works like 'eval', but sends the SHA1 hash of the script instead of the script itself.
+-- Fails if the server does not recognise the hash, in which case, 'eval' should be used instead.
 evalsha
     :: (RedisCtx m f, RedisResult a)
-    => ByteString -- ^ script
+    => ByteString -- ^ base16-encoded sha1 hash of the script
     -> [ByteString] -- ^ keys
     -> [ByteString] -- ^ args
     -> m (f a)