diff --git a/Changelog.md b/Changelog.md
index 8a9a1699..ceacc3b6 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,44 @@
+[0.13.0.0] — circa 2026-2027
+
+* __Breaking Changes__:
+  * [`Data.Data.dataTypeOf` for `StrictByteString` and `LazyByteString` now returns a `DataType` that uses `AlgRep` instead of `NoRep`.](https://github.com/haskell/bytestring/pull/614)
+    * This allows utilities like `syb:Data.Generics.Text.gread` to be meaningfully used at these types containing `ByteString`s.
+  * [`fromListN` in `instance IsList ByteString` truncates input list if it's longer than the size hint](https://github.com/haskell/bytestring/pull/672)
+<!--
+* Bug fixes:
+* API additions and behavior changes:
+* Deprecations:
+* Performance improvements:
+* Miscellaneous:
+* Internal stuff:
+-->
+
+[0.12.2.0] — December 2024
+
+* Bug fixes:
+  * [`Builder`: avoid unsound buffer reuse, introduced in `bytestring-0.11.5.0`](https://github.com/haskell/bytestring/pull/691)
+  * [Fix several bugs around the `byteString` family of `Builders`](https://github.com/haskell/bytestring/pull/671)
+  * [Make `Data.ByteString.Lazy.zipWith` properly lazy](https://github.com/haskell/bytestring/pull/668)
+* API additions:
+  * [Add `instance IsList Builder`](https://github.com/haskell/bytestring/pull/672)
+  * [Add `instance NFData BufferRange` and `instance NFData Buffer`](https://github.com/haskell/bytestring/pull/680)
+  * [Export `toLazyByteString` from `Data.ByteString.Builder.Internal`](https://github.com/haskell/bytestring/pull/672)
+* Performance improvements:
+  * [Remove another dead branch from `toStrict`](https://github.com/haskell/bytestring/pull/663)
+* Miscellaneous:
+  * [Remove support for GHC < 8.4](https://github.com/haskell/bytestring/pull/682)
+  * Various documentation improvements ([1](https://github.com/haskell/bytestring/pull/683), [2](https://github.com/haskell/bytestring/pull/692))
+<!--
+* Internal stuff:
+  * Various CI tweaks ([1](https://github.com/haskell/bytestring/pull/670), [2](https://github.com/haskell/bytestring/pull/681), [3](https://github.com/haskell/bytestring/pull/686), [4](https://github.com/haskell/bytestring/pull/656), [5](https://github.com/haskell/bytestring/pull/693), [6](https://github.com/haskell/bytestring/pull/699), [7](https://github.com/haskell/bytestring/pull/700))
+  * [Use `default-extensions` to tidy up a bit](https://github.com/haskell/bytestring/pull/669)
+  * [Remove `includes` from Cabal file](https://github.com/haskell/bytestring/pull/685)
+  * [Improve benchmarks for small `Builders`](https://github.com/haskell/bytestring/pull/680)
+  * [Add a constraint reflecting](https://github.com/haskell/bytestring/pull/698) [#665](https://github.com/haskell/bytestring/issues/665) [to the package description](https://github.com/haskell/bytestring/pull/698)
+-->
+
+[0.12.2.0]: https://github.com/haskell/bytestring/compare/0.12.1.0...0.12.2.0
+
 [0.12.1.0] — February 2024
 
 * [Provisional support has been added for using `bytestring` with GHC's JavaScript back-end.](https://github.com/haskell/bytestring/pull/631)