diff --git a/cabal.project b/cabal.project
index afba260..19eb2c6 100644
--- a/cabal.project
+++ b/cabal.project
@@ -1,3 +1,2 @@
 packages:
   ./witherable/
-  ./witherable-class/
diff --git a/witherable-class/CHANGELOG.md b/witherable-class/CHANGELOG.md
deleted file mode 100644
index dbb7e26..0000000
--- a/witherable-class/CHANGELOG.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Revision history for witherable-class
-
-## 0.0.1
-
-* Package is deprecated. Use `witherable`.
-
-## 0 - 2019/12/20
-
-* First version. Released on an unsuspecting world.
diff --git a/witherable-class/Data/Witherable/Class.hs b/witherable-class/Data/Witherable/Class.hs
deleted file mode 100644
index de87540..0000000
--- a/witherable-class/Data/Witherable/Class.hs
+++ /dev/null
@@ -1,9 +0,0 @@
-module Data.Witherable.Class
-  {-# DEPRECATED "Import Witherable instead" #-}
-  ( Filterable(..)
-  , Witherable(..)
-  , FilterableWithIndex(..)
-  , WitherableWithIndex(..)
-  ) where
-
-import Witherable
\ No newline at end of file
diff --git a/witherable-class/LICENSE b/witherable-class/LICENSE
deleted file mode 100644
index 1994a4c..0000000
--- a/witherable-class/LICENSE
+++ /dev/null
@@ -1,30 +0,0 @@
-Copyright (c) 2014, Fumiaki Kinoshita
-
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-    * Redistributions of source code must retain the above copyright
-      notice, this list of conditions and the following disclaimer.
-
-    * Redistributions in binary form must reproduce the above
-      copyright notice, this list of conditions and the following
-      disclaimer in the documentation and/or other materials provided
-      with the distribution.
-
-    * Neither the name of Fumiaki Kinoshita nor the names of other
-      contributors may be used to endorse or promote products derived
-      from this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/witherable-class/Main.hs b/witherable-class/Main.hs
deleted file mode 100644
index 60d904e..0000000
--- a/witherable-class/Main.hs
+++ /dev/null
@@ -1,8 +0,0 @@
-module Main where
-
-import qualified MyLib (someFunc)
-
-main :: IO ()
-main = do
-  putStrLn "Hello, Haskell!"
-  MyLib.someFunc
diff --git a/witherable-class/Setup.hs b/witherable-class/Setup.hs
deleted file mode 100644
index 9a994af..0000000
--- a/witherable-class/Setup.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-import Distribution.Simple
-main = defaultMain
diff --git a/witherable-class/witherable-class.cabal b/witherable-class/witherable-class.cabal
deleted file mode 100644
index 045c32e..0000000
--- a/witherable-class/witherable-class.cabal
+++ /dev/null
@@ -1,26 +0,0 @@
-cabal-version:       2.4
-name:                witherable-class
-version:             0.0.1
-synopsis:            Witherable = Traversable + Filterable
-description:         This package is deprecated. Use the witherable package instead
-bug-reports:         https://github.com/fumieval/witherable
-license:             BSD-3-Clause
-license-file:        LICENSE
-author:              Fumiaki Kinoshita
-maintainer:          fumiexcel@gmail.com
-copyright:           Copyright (c) 2021 Fumiaki Kinoshita
-category:            Data
-extra-source-files:  CHANGELOG.md
-tested-with:         GHC ==8.0.2 || ==8.2.2 || ==8.4.4 || ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.1 || ==0.2.1
-
-source-repository head
-  type: git
-  location: git@github.com:fumieval/witherable.git
-  subdir: witherable-class
-
-library
-  exposed-modules:     Data.Witherable.Class
-  build-depends:       base >= 4.9 && <5
-                     , witherable ^>= 0.4
-  default-language:    Haskell2010
-  ghc-options:         -Wall -Wcompat
diff --git a/witherable/CHANGELOG.md b/witherable/CHANGELOG.md
index 1ba01b3..7f0df82 100644
--- a/witherable/CHANGELOG.md
+++ b/witherable/CHANGELOG.md
@@ -1,3 +1,8 @@
+0.5
+---
+
+* `FilterableWithIndex` is a superclass of `WitherableWithIndex`.
+
 0.4.2
 -------
 
diff --git a/witherable/witherable.cabal b/witherable/witherable.cabal
index df52459..3d9395d 100644
--- a/witherable/witherable.cabal
+++ b/witherable/witherable.cabal
@@ -1,7 +1,6 @@
 cabal-version:       2.4
 name:                witherable
-version:             0.4.2
-x-revision:          3
+version:             0.5
 synopsis:            filterable traversable
 description:         A stronger variant of `traverse` which can remove elements and generalised mapMaybe, catMaybes, filter
 homepage:            https://github.com/fumieval/witherable