diff --git a/formatn.cabal b/formatn.cabal
--- a/formatn.cabal
+++ b/formatn.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: formatn
-version: 0.3.1.0
+version: 0.3.1.1
 license: BSD-3-Clause
 license-file: LICENSE
 copyright: Tony Day (c) 2016
@@ -11,57 +11,78 @@
 bug-reports: https://github.com/tonyday567/formatn/issues
 synopsis: Formatting of doubles.
 description:
-    This package provides support for number formatting styles, especially styles involving significant figure calculations.
+  This package provides support for number formatting styles, especially styles involving significant figure calculations.
 
-    == Usage
+  == Usage
 
-    >>> import Data.FormatN
-    >>> comma (Just 3) 1234
-    1,230
+  >>> import Data.FormatN
+  >>> comma (Just 3) 1234
+  1,230
 
 build-type: Simple
 tested-with:
-    , GHC == 9.10.1
-    , GHC == 9.6.5
-    , GHC == 9.8.2
+  ghc ==9.6.7
+  ghc ==9.8.4
+  ghc ==9.10.2
+  ghc ==9.12.2
+
 extra-doc-files:
-    ChangeLog.md
-    readme.md
+  ChangeLog.md
+  readme.md
 
 source-repository head
-    type: git
-    location: https://github.com/tonyday567/formatn
+  type: git
+  location: https://github.com/tonyday567/formatn
 
 common ghc-options-stanza
-    ghc-options:
-        -Wall
-        -Wcompat
-        -Widentities
-        -Wincomplete-record-updates
-        -Wincomplete-uni-patterns
-        -Wpartial-fields
-        -Wredundant-constraints
+  ghc-options:
+    -Wall
+    -Wcompat
+    -Widentities
+    -Wincomplete-record-updates
+    -Wincomplete-uni-patterns
+    -Wpartial-fields
+    -Wredundant-constraints
 
-common ghc2021-stanza
-    default-language: GHC2021
+common ghc2024-additions
+  default-extensions:
+    DataKinds
+    DerivingStrategies
+    DisambiguateRecordFields
+    ExplicitNamespaces
+    GADTs
+    LambdaCase
+    MonoLocalBinds
+    RoleAnnotations
 
+common ghc2024-stanza
+  if impl(ghc >=9.10)
+    default-language:
+      GHC2024
+  else
+    import: ghc2024-additions
+    default-language:
+      GHC2021
+
 library
-    import: ghc-options-stanza
-    import: ghc2021-stanza
-    hs-source-dirs: src
-    build-depends:
-        , base       >=4.14 && <5
-        , containers >=0.6 && <0.8
-        , text       >=1.2 && <2.2
-    exposed-modules: Data.FormatN
+  import: ghc-options-stanza
+  import: ghc2024-stanza
+  hs-source-dirs: src
+  build-depends:
+    base >=4.14 && <5,
+    containers >=0.6 && <0.9,
+    text >=1.2 && <2.2,
 
+  exposed-modules: Data.FormatN
+
 test-suite doctests
-    import: ghc2021-stanza
-    main-is: doctests.hs
-    hs-source-dirs: test
-    build-depends:
-        , QuickCheck       >=2.14.2 && <2.16
-        , base             >=4.14 && <5
-        , doctest-parallel >=0.3 && <0.4
-    ghc-options: -threaded
-    type: exitcode-stdio-1.0
+  import: ghc2024-stanza
+  main-is: doctests.hs
+  hs-source-dirs: test
+  build-depends:
+    QuickCheck >=2.14.2 && <2.17,
+    base >=4.14 && <5,
+    doctest-parallel >=0.3 && <0.5,
+
+  ghc-options: -threaded
+  type: exitcode-stdio-1.0
diff --git a/readme.md b/readme.md
--- a/readme.md
+++ b/readme.md
@@ -1,14 +1,10 @@
-
-# formatn 
-
-[![img](https://img.shields.io/hackage/v/formatn.svg)](https://hackage.haskell.org/package/formatn) [![img](https://github.com/tonyday567/formatn/workflows/haskell-ci/badge.svg)](https://github.com/tonyday567/formatn/actions?query=workflow%3Ahaskell-ci)
+[![img](https://img.shields.io/hackage/v/formatn.svg)](https://hackage.haskell.org/package/formatn) [![img](https://github.com/tonyday567/formatn/actions/workflows/haskell-ci.yml/badge.svg)](https://github.com/tonyday567/formatn/actions/workflows/haskell-ci.yml)
 
 A library for support of:
 
 -   significant figure rounding of numbers, and
 -   common number formatting patterns.
 
-<a id="org95ded84"></a>
 
 # Usage
 
@@ -37,13 +33,9 @@
     ["-1.00","0.00","0.10","1.00","1.01","1.02","1.10","1.20"]
 
 
-<a id="orgb82f98d"></a>
-
 # getting 0 right
 
 
-<a id="orgaf42992"></a>
-
 ## fixed
 
     fixed (Just 3) <$> [0, 0.5, 1.5, 2.0]
@@ -57,8 +49,6 @@
     ["0.0","0.5","1.5","2.0"]
 
 
-<a id="org1b53172"></a>
-
 ## expt
 
     expt Nothing 0
@@ -72,8 +62,6 @@
     0.0e0
 
 
-<a id="org90e32fb"></a>
-
 ## decimal
 
     decimal Nothing 0
@@ -85,8 +73,6 @@
     0.00
 
 
-<a id="orgbe4b502"></a>
-
 ## percent
 
 percent is a little weird any way you cut it.
@@ -97,8 +83,6 @@
     0.0%
     100.0%
 
-
-<a id="org549dfe5"></a>
 
 ## inclusion in lists