diff --git a/aggreact.cabal b/aggreact.cabal
index 9ecfc7c..c1cd3fb 100644
--- a/aggreact.cabal
+++ b/aggreact.cabal
@@ -2,7 +2,7 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 745ba9e49439490ae68f7ebc35693766acc2a95eb17b9494150582812aa83cef
+-- hash: 1045a6f370c70bdbb8d4127fd57ab0a6d22abf83a1c9ce43b2543665b731e255
 
 name:           aggreact
 version:        0.1.0.0
@@ -41,6 +41,8 @@ library
       aeson
     , base >=4.8 && <5
     , cereal
+    , cereal-text
+    , cereal-time
     , containers
     , ixset
     , protolude
diff --git a/package.yaml b/package.yaml
index f88e5cc..a0dd0b3 100644
--- a/package.yaml
+++ b/package.yaml
@@ -29,6 +29,8 @@ library:
   dependencies:
   - aeson
   - cereal
+  - cereal-text
+  - cereal-time
   - containers
   - ixset
   - servant
diff --git a/src/Aggreact/Comments.hs b/src/Aggreact/Comments.hs
index 470db66..5267dd9 100644
--- a/src/Aggreact/Comments.hs
+++ b/src/Aggreact/Comments.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveAnyClass       #-}
+{-# LANGUAGE DeriveDataTypeable   #-}
 {-# LANGUAGE DeriveGeneric        #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE StandaloneDeriving   #-}
@@ -25,16 +26,20 @@ module Aggreact.Comments
   , Comments
   ) where
 
-import           Protolude       hiding (get, put)
+import           Protolude                 hiding (get, put)
 
-import           Data.Aeson      (FromJSON, ToJSON)
-import           Data.IxSet      ((@=))
-import qualified Data.IxSet      as IxSet
-import           Data.Serialize  (Serialize (..))
-import qualified Data.Text       as Text
-import           Data.Time       (UTCTime)
-import           Data.Tree       (Tree (..))
-import           Data.Typeable   (Typeable)
+import           Data.Aeson                (FromJSON, ToJSON)
+import           Data.Char                 (isAlphaNum)
+import           Data.Data                 (Data (..))
+import           Data.IxSet                ((@=))
+import qualified Data.IxSet                as IxSet
+import           Data.Serialize            (Serialize (..))
+import           Data.Serialize.Text       ()
+import qualified Data.Text                 as Text
+import           Data.Time                 (UTCTime)
+import           Data.Time.Clock.Serialize ()
+import           Data.Tree                 (Tree (..))
+import           Data.Typeable             (Typeable)
 
 import           Versioning.Base
 
@@ -51,7 +56,6 @@ instance ( Serialize a
   put i = put (IxSet.toList i)
   get   = fmap IxSet.fromList get
 
-
 -- * Comment
 
 newtype Id       = Id Int64       deriving (Eq,Ord,Generic)
@@ -75,9 +79,6 @@ deriving instance ToJSON    Content
 deriving instance Serialize Content
 
 newtype Term     = Term Text      deriving (Eq,Ord,Generic)
-deriving instance FromJSON  Term
-deriving instance ToJSON    Term
-deriving instance Serialize Term
 
 data Comment v =
   Comment
@@ -86,7 +87,7 @@ data Comment v =
   , created :: UTCTime
   , content :: Content
   , userid  :: Since V0 v UserId
-  } deriving (Generic)
+  } deriving (Generic,Typeable,Data)
 
 deriving instance FromJSON  (Comment V0)
 deriving instance ToJSON    (Comment V0)