diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for fold-debounce-conduit
 
+## 0.2.0.6  -- 2021-02-28
+
+* Confirm test with `base-4.15.0.0` (ghc-9.0.1)
+
 ## 0.2.0.5  -- 2020-06-21
 
 * Confirm test with `base-4.14.0.0` (ghc-8.10.1)
diff --git a/fold-debounce-conduit.cabal b/fold-debounce-conduit.cabal
--- a/fold-debounce-conduit.cabal
+++ b/fold-debounce-conduit.cabal
@@ -1,5 +1,5 @@
 name:                   fold-debounce-conduit
-version:                0.2.0.5
+version:                0.2.0.6
 author:                 Toshio Ito <debug.ito@gmail.com>
 maintainer:             Toshio Ito <debug.ito@gmail.com>
 license:                BSD3
@@ -20,7 +20,7 @@
   exposed-modules:      Data.Conduit.FoldDebounce
   -- other-modules:
   default-extensions:   FlexibleContexts
-  build-depends:        base >=4.9.0 && <4.15,
+  build-depends:        base >=4.9.0 && <4.16,
                         conduit >=1.3.0 && <1.4,
                         fold-debounce >=0.2.0 && <0.3,
                         resourcet >=1.2.0 && <1.3,
@@ -44,6 +44,7 @@
   ghc-options:          -Wall -fno-warn-unused-imports "-with-rtsopts=-M512m"
   main-is:              Spec.hs
   other-modules:        Data.Conduit.FoldDebounceSpec
+  build-tool-depends:   hspec-discover:hspec-discover
   build-depends:        base, fold-debounce-conduit, stm,
                         conduit, transformers, resourcet,
                         hspec >=2.1.7