diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+0.2.5.1 (2021.10.16):
+    - Fixing things to compile under GHC 9.0
+0.2.5.0 (2019.02.25):
+    - Fixing things to compile under GHC 8.4 and 8.6.
+	- Adds Semigroup (Trie a) instance
+	- Removed the obsolete/unused "useCinternal" Cabal flag
 0.2.4.3 (2019.02.24):
     - Moved VERSION to CHANGELOG
     - Fixing things to compile under GHC 8.0 and 8.2.  N.B., still doesn't compile under 8.4 or 8.6, due to the version limit on `base`.
diff --git a/bytestring-trie.cabal b/bytestring-trie.cabal
--- a/bytestring-trie.cabal
+++ b/bytestring-trie.cabal
@@ -1,21 +1,18 @@
 ------------------------------------------------------------
--- wren gayle romano <wren@cpan.org>            ~ 2019.02.25
+-- wren gayle romano <wren@cpan.org>            ~ 2021.10.16
 ------------------------------------------------------------
 
--- By and large Cabal >=1.2 is fine; but
--- * >=1.6 gives tested-with: and source-repository:
--- * >=1.8 allows executables to build-depends: on the library
--- * >=1.9.2 allows Test-Suite
-Cabal-Version:  >= 1.9.2
+-- Cabal >=1.10 is required by Hackage.
+Cabal-Version:  >= 1.10
 Build-Type:     Simple
 
 Name:           bytestring-trie
-Version:        0.2.5.0
+Version:        0.2.5.1
 Stability:      provisional
 Homepage:       http://wrengr.org
 Author:         wren gayle romano
 Maintainer:     wren@cpan.org
-Copyright:      Copyright (c) 2008--2019 wren gayle romano
+Copyright:      Copyright (c) 2008--2021 wren gayle romano
 License:        BSD3
 License-File:   LICENSE
 
@@ -55,7 +52,8 @@
     GHC ==8.0.1, GHC ==8.0.2,
     GHC ==8.2.1, GHC ==8.2.2,
     GHC ==8.4.1, GHC ==8.4.2, GHC ==8.4.3,
-    GHC ==8.6.1, GHC ==8.6.2
+    GHC ==8.6.1, GHC ==8.6.2,
+    GHC ==9.0.1
 
 Source-Repository head
     Type:     git
@@ -63,6 +61,7 @@
 
 ------------------------------------------------------------
 Library
+    Default-Language: Haskell2010
     Hs-Source-Dirs:  src
     Exposed-Modules: Data.Trie
                    , Data.Trie.Internal
@@ -73,9 +72,9 @@
     -- The lower bounds are more restrictive than necessary.
     -- But then, we don't maintain any CI tests for older
     -- versions, so these are the lowest bounds we've verified.
-    Build-Depends: base       >= 4.5   && < 4.13
+    Build-Depends: base       >= 4.5   && < 4.16
                  , bytestring >= 0.9.2 && < 0.11
-                 , binary     >= 0.5.1 && < 0.8.7
+                 , binary     >= 0.5.1 && < 0.8.9
     
 ------------------------------------------------------------
 ------------------------------------------------------- fin.