diff --git a/CHANGELOG.md b/CHANGELOG.md
index 844c2b4..5ce9c80 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,18 @@
 
 _**If you are upgrading:** please see [`UPGRADING.md`](https://github.com/Level/memdown/blob/master/UPGRADING.md)._
 
+## [6.0.0] - 2021-04-10
+
+### Changed
+
+- **Breaking:** bump `abstract-leveldown` ([`4e2f320`](https://github.com/Level/memdown/commit/4e2f320), [`dee72a3`](https://github.com/Level/memdown/commit/dee72a3)) (Vincent Weevers)
+- **Breaking:** drop node 6 and 8 ([Level/community#98](https://github.com/Level/community/issues/98)) ([`3708b5f`](https://github.com/Level/memdown/commit/3708b5f)) (Vincent Weevers)
+- **Breaking:** modernize syntax and bump `standard` ([Level/community#98](https://github.com/Level/community/issues/98)) ([`c1f98c3`](https://github.com/Level/memdown/commit/c1f98c3)) (Vincent Weevers)
+- Use `_nextTick()` utility for browsers ([`ba525c4`](https://github.com/Level/memdown/commit/ba525c4)) (Vincent Weevers)
+- Replace `safe-buffer` with `buffer` ([`d3dab23`](https://github.com/Level/memdown/commit/d3dab23)) (Vincent Weevers)
+- Remove default export ([Level/community#87](https://github.com/Level/community/issues/87)) ([`5fd8368`](https://github.com/Level/memdown/commit/5fd8368)) (Vincent Weevers)
+- Unlock dependencies ([`7126df1`](https://github.com/Level/memdown/commit/7126df1)) (Vincent Weevers)
+
 ## [5.1.0] - 2019-10-04
 
 ### Changed
@@ -140,6 +152,8 @@ _**If you are upgrading:** please see [`UPGRADING.md`](https://github.com/Level/
 - Remove unnecessary `rimraf` replacement for Browserify ([**@vweevers**](https://github.com/vweevers))
 - README: remove Greenkeeper badge ([**@ralphtheninja**](https://github.com/ralphtheninja))
 
+[6.0.0]: https://github.com/Level/memdown/compare/v5.1.0...v6.0.0
+
 [5.1.0]: https://github.com/Level/memdown/compare/v5.0.0...v5.1.0
 
 [5.0.0]: https://github.com/Level/memdown/compare/v4.1.0...v5.0.0
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index 7f602fd..c510a2a 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -1,20 +1,20 @@
 # Contributors
 
-| Name                 | GitHub                                                 | Social                                                        |
-| :------------------- | :----------------------------------------------------- | :------------------------------------------------------------ |
-| **Vincent Weevers**  | [**@vweevers**](https://github.com/vweevers)           | [**@vweevers@twitter**](https://twitter.com/vweevers)         |
-| **Rod Vagg**         | [**@rvagg**](https://github.com/rvagg)                 | [**@rvagg@twitter**](https://twitter.com/rvagg)               |
-| **Nolan Lawson**     | [**@nolanlawson**](https://github.com/nolanlawson)     | [**@nolan@toot.cafe**](https://toot.cafe/@nolan)              |
-| **Calvin Metcalf**   | [**@calvinmetcalf**](https://github.com/calvinmetcalf) |                                                               |
-| **Lars-Magnus Skog** | [**@ralphtheninja**](https://github.com/ralphtheninja) | [**@ralph@social.weho.st**](https://social.weho.st/@ralph)    |
-| **Julian Gruber**    | [**@juliangruber**](https://github.com/juliangruber)   | [**@juliangruber@twitter**](https://twitter.com/juliangruber) |
-| **Meirion Hughes**   | [**@MeirionHughes**](https://github.com/MeirionHughes) |                                                               |
-| **Dominic Tarr**     | [**@dominictarr**](https://github.com/dominictarr)     | [**@dominictarr@twitter**](https://twitter.com/dominictarr)   |
-| **Mathias Buus**     | [**@mafintosh**](https://github.com/mafintosh)         | [**@mafintosh@twitter**](https://twitter.com/mafintosh)       |
-| **Michael Hart**     | [**@mhart**](https://github.com/mhart)                 | [**@hichaelmart@twitter**](https://twitter.com/hichaelmart)   |
-| **Max Ogden**        | [**@maxogden**](https://github.com/maxogden)           | [**@maxogden@twitter**](https://twitter.com/maxogden)         |
-| **Kirill Fomichev**  | [**@fanatid**](https://github.com/fanatid)             |                                                               |
-| **kumavis**          | [**@kumavis**](https://github.com/kumavis)             |                                                               |
-| **Marco Oliveira**   | [**@marcooliveira**](https://github.com/marcooliveira) | [**@sonicspot@twitter**](https://twitter.com/sonicspot)       |
-| **Tim Oxley**        | [**@timoxley**](https://github.com/timoxley)           | [**@secoif@twitter**](https://twitter.com/secoif)             |
-| **Will White**       | [**@willwhite**](https://github.com/willwhite)         |                                                               |
+| Name                 | GitHub                                                       | Social                                                        |
+| :------------------- | :----------------------------------------------------------- | :------------------------------------------------------------ |
+| **Vincent Weevers**  | [**@vweevers**](https://github.com/vweevers)                 | [**@vweevers@twitter**](https://twitter.com/vweevers)         |
+| **Rod Vagg**         | [**@rvagg**](https://github.com/rvagg)                       | [**@rvagg@twitter**](https://twitter.com/rvagg)               |
+| **Nolan Lawson**     | [**@nolanlawson**](https://github.com/nolanlawson)           | [**@nolan@toot.cafe**](https://toot.cafe/@nolan)              |
+| **Calvin Metcalf**   | [**@calvinmetcalf**](https://github.com/calvinmetcalf)       |                                                               |
+| **Lars-Magnus Skog** | [**@ralphtheninja**](https://github.com/ralphtheninja)       | [**@ralph@social.weho.st**](https://social.weho.st/@ralph)    |
+| **Julian Gruber**    | [**@juliangruber**](https://github.com/juliangruber)         | [**@juliangruber@twitter**](https://twitter.com/juliangruber) |
+| **Meirion Hughes**   | [**@MeirionHughes**](https://github.com/MeirionHughes)       |                                                               |
+| **Dominic Tarr**     | [**@dominictarr**](https://github.com/dominictarr)           | [**@dominictarr@twitter**](https://twitter.com/dominictarr)   |
+| **Mathias Buus**     | [**@mafintosh**](https://github.com/mafintosh)               | [**@mafintosh@twitter**](https://twitter.com/mafintosh)       |
+| **Michael Hart**     | [**@mhart**](https://github.com/mhart)                       | [**@hichaelmart@twitter**](https://twitter.com/hichaelmart)   |
+| **Max Ogden**        | [**@maxogden**](https://github.com/maxogden)                 | [**@maxogden@twitter**](https://twitter.com/maxogden)         |
+| **Kirill Fomichev**  | [**@fanatid**](https://github.com/fanatid)                   |                                                               |
+| **kumavis**          | [**@kumavis**](https://github.com/kumavis)                   |                                                               |
+| **Marco Oliveira**   | [**@marcooliveira**](https://github.com/marcooliveira)       | [**@sonicspot@twitter**](https://twitter.com/sonicspot)       |
+| **Tim Oxley**        | [**@timoxley**](https://github.com/timoxley)                 | [**@secoif@twitter**](https://twitter.com/secoif)             |
+| **Will White**       | [**@willwhite**](https://github.com/willwhite)               |                                                               |
diff --git a/UPGRADING.md b/UPGRADING.md
index 754945c..9129806 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -2,11 +2,34 @@
 
 This document describes breaking changes and how to upgrade. For a complete list of changes including minor and patch releases, please refer to the [`CHANGELOG`][changelog].
 
-## v5
+## 6.0.0
+
+Legacy range options have been removed ([Level/community#86](https://github.com/Level/community/issues/86)). If you previously did:
+
+```js
+db.iterator({ start: 'a', end: 'z' })
+```
+
+An error would now be thrown and you must instead do:
+
+```js
+db.iterator({ gte: 'a', lte: 'z' })
+```
+
+This release also drops support of legacy runtime environments ([Level/community#98](https://github.com/Level/community/issues/98)):
+
+- Node.js 6 and 8
+- Internet Explorer 11
+- Safari 9-11
+- Stock Android browser (AOSP).
+
+Lastly, and less likely to be a breaking change, the [`immediate`](https://github.com/calvinmetcalf/immediate) browser shim for `process.nextTick()` has been replaced with the smaller [`queue-microtask`](https://github.com/feross/queue-microtask).
+
+## 5.0.0
 
 Support of keys & values other than strings and Buffers has been dropped. Internally `memdown` now stores keys & values as Buffers which solves a number of compatibility issues ([#186](https://github.com/Level/memdown/issues/186)). If you pass in a key or value that isn't a string or Buffer, it will be irreversibly stringified.
 
-## v4
+## 4.0.0
 
 This is an upgrade to `abstract-leveldown@6` which solves long-standing issues around serialization and type support.
 
@@ -32,11 +55,11 @@ Though this was already the case, `abstract-leveldown` has replaced the behavior
 
 IE10 has been dropped.
 
-## v3
+## 3.0.0
 
 Dropped support for node 4. No other breaking changes.
 
-## v2
+## 2.0.0
 
 This release drops Node.js 0.12, brings `memdown` up to par with latest [`levelup`][levelup] (v2) and [`abstract-leveldown`][abstract-leveldown] (v4), simplifies serialization and removes global state.
 
diff --git a/package.json b/package.json
index e5bbc31..15f968e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "memdown",
-  "version": "5.1.0",
+  "version": "6.0.0",
   "description": "An drop-in replacement for LevelDOWN that works in memory only",
   "authors": [
     "Rod Vagg <rod@vagg.org> (https://github.com/rvagg)"