diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # ChangeLog for tls-session-manager
 
+## 0.0.8
+
+* Removing "basement".
+
 ## 0.0.7
 
 * Naming threads.
diff --git a/Network/TLS/SessionManager.hs b/Network/TLS/SessionManager.hs
--- a/Network/TLS/SessionManager.hs
+++ b/Network/TLS/SessionManager.hs
@@ -13,11 +13,12 @@
     dbMaxSize,
 ) where
 
-import Basement.Block (Block)
 import Control.Exception (assert)
 import Control.Reaper
 import Data.ByteArray (convert)
 import Data.ByteString (ByteString)
+import Data.ByteString.Short (ShortByteString)
+import qualified Data.ByteString.Short as SBS
 import Data.IORef
 import Data.OrdPSQ (OrdPSQ)
 import qualified Data.OrdPSQ as Q
@@ -49,8 +50,8 @@
 
 ----------------------------------------------------------------
 
-toKey :: ByteString -> Block Word8
-toKey = convert
+toKey :: ByteString -> SessionIDCopy
+toKey = SBS.toShort
 
 toValue :: SessionData -> SessionDataCopy
 toValue sd =
@@ -69,7 +70,7 @@
 
 ----------------------------------------------------------------
 
-type SessionIDCopy = Block Word8
+type SessionIDCopy = ShortByteString
 newtype SessionDataCopy = SessionDataCopy SessionData
     deriving (Show, Eq)
 
diff --git a/tls-session-manager.cabal b/tls-session-manager.cabal
--- a/tls-session-manager.cabal
+++ b/tls-session-manager.cabal
@@ -1,6 +1,6 @@
 cabal-version:      >=1.10
 name:               tls-session-manager
-version:            0.0.7
+version:            0.0.8
 license:            BSD3
 license-file:       LICENSE
 maintainer:         kazu@iij.ad.jp
@@ -21,8 +21,7 @@
     ghc-options:      -Wall
     build-depends:
         base >=4.7 && <5,
-        auto-update >= 0.1 && < 0.3,
-        basement >= 0.0.16 && < 0.1,
+        auto-update >= 0.2.2 && < 0.3,
         bytestring >= 0.10 && < 0.13,
         clock >= 0.8 && < 0.9,
         crypto-token >= 0.1.2 && < 0.2,