diff --git a/.gitignore b/.gitignore
deleted file mode 100644
--- a/.gitignore
+++ /dev/null
@@ -1,22 +0,0 @@
-/.HTF/
-/.stack-work
-/.vscode
-/bench
-/examples
-/.gitignore
-/doldol.cabal
-/stack.yaml
-/stack.yaml.lock
-*.o
-*.hi
-*.chi
-*.chs.h
-*.dyn_o
-*.dyn_hi
-.hpc
-*.prof
-*.aux
-*.hp
-*.eventlog
-/test/Test.hs
-/install.sh
diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-  "languageServerHaskell.useCustomHieWrapper": true,
-  "languageServerHaskell.useCustomHieWrapperPath": "t:\\QJoon\\VSCode\\hie.bat",
-  "cSpell.words": [
-    "hunit",
-    "newtype"
-  ]
-}
diff --git a/doldol.cabal b/doldol.cabal
--- a/doldol.cabal
+++ b/doldol.cabal
@@ -1,17 +1,11 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.31.2.
---
--- see: https://github.com/sol/hpack
---
--- hash: 95b2ef45e98d851f82b0289b799a83f6b4f5b932966b4ead1ce5700d320f16da
-
 name:           doldol
-version:        0.4.1.0
+version:        0.4.1.1
 synopsis:       Flag packer & handler for flaggable data
 description:    Please see the README on GitHub at <https://github.com/QuietJoon/doldol#readme>
 category:       Data
-homepage:       https://github.com/QuietJoon/doldol/
+homepage:       https://github.com/QuietJoon/doldol
 bug-reports:    https://github.com/QuietJoon/doldol/issues
 author:         YongJoon Joe
 maintainer:     developer+doldol@quietjoon.net
@@ -36,7 +30,7 @@
   hs-source-dirs:
       src
   build-depends:
-      base >=4.7 && <5
+      base >=4.4 && <5
   default-language: Haskell2010
 
 test-suite doldol-test
@@ -55,7 +49,7 @@
   build-depends:
       HUnit
     , QuickCheck
-    , base >=4.7
+    , base >=4.4 && <5
     , doldol
     , test-framework
     , test-framework-hunit
diff --git a/src/Data/Flag/Phantom.hs b/src/Data/Flag/Phantom.hs
--- a/src/Data/Flag/Phantom.hs
+++ b/src/Data/Flag/Phantom.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE RankNTypes, GeneralizedNewtypeDeriving #-}
-
 -- | `Data.Flag.Phantom` is for strict typing of Flag.
 --
 --   When you want to distinguish two Flag by its origination, use this module instead of `Data.Flag`(`Data.Flag.Simple`).
@@ -8,6 +6,8 @@
   , module Data.Flag.Internal
   ) where
 
+
+import Data.Foldable -- For base-4.7.0.*
 
 import Data.Flag.Internal
 import qualified Data.Flag.Simple as SF
diff --git a/src/Data/Flag/Simple.hs b/src/Data/Flag/Simple.hs
--- a/src/Data/Flag/Simple.hs
+++ b/src/Data/Flag/Simple.hs
@@ -12,6 +12,7 @@
 #endif
 
 import Data.Bits
+import Data.Foldable -- For base-4.7.0.*
 
 import GHC.Base