diff --git a/CHANGELOG.md b/CHANGELOG.md
index b19d478..4fb0ca4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # changelog
 
+## 0.10.0
+
+* Complete rewrite, resulting in ~40x speed increase ([#30](https://github.com/Rich-Harris/magic-string/pull/30))
+* Breaking – `magicString.locate` and `locateOrigin` are deprecated
+* More forgiving rules about contiguous patches, and which ranges are valid with `magicString.slice(...)`
+
 ## 0.9.1
 
 * Update deps
diff --git a/README.md b/README.md
index 7fad524..ef6eadd 100644
--- a/README.md
+++ b/README.md
@@ -52,8 +52,6 @@ var s = new MagicString( 'problems = 99' );
 
 s.overwrite( 0, 8, 'answer' );
 s.toString(); // 'answer = 99'
-s.locate( 9 ); // 7 - the character originally at index 9 ('=') is now at index 7
-s.locateOrigin( 7 ); // 9
 
 s.overwrite( 11, 13, '42' ); // character indices always refer to the original string
 s.toString(); // 'answer = 42'
@@ -126,11 +124,11 @@ Inserts the specified `content` at the `index` in the original string. Returns `
 
 ### s.locate( index )
 
-Finds the location, in the generated string, of the character at `index` in the original string. Returns `null` if the character in question has been removed or overwritten.
+**DEPRECATED** since 0.10 – see [#30](https://github.com/Rich-Harris/magic-string/pull/30)
 
 ### s.locateOrigin( index )
 
-The opposite of `s.locate()`. Returns `null` if the character in question was inserted with `s.append()`, `s.prepend()` or `s.overwrite()`.
+**DEPRECATED** since 0.10 – see [#30](https://github.com/Rich-Harris/magic-string/pull/30)
 
 ### s.overwrite( start, end, content[, storeName] )
 
diff --git a/package.json b/package.json
index 17f2b74..4347b62 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "magic-string",
   "description": "Modify strings, generate sourcemaps",
   "author": "Rich Harris",
-  "version": "0.9.1",
+  "version": "0.10.0",
   "repository": "https://github.com/rich-harris/magic-string",
   "main": "dist/magic-string.cjs.js",
   "jsnext:main": "dist/magic-string.es6.js",