diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9564615eb..d228f8e66 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+## 5.6.1 (2018-06-01)
+
+### Bug fixes
+
+Fix regression when passing `null` as fourth argument to `walk.recursive`.
+
 ## 5.6.0 (2018-05-31)
 
 ### Bug fixes
diff --git a/package.json b/package.json
index 63f1c7a43..aff84b723 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "homepage": "https://github.com/acornjs/acorn",
   "main": "dist/acorn.js",
   "module": "dist/acorn.es.js",
-  "version": "5.6.0",
+  "version": "5.6.1",
   "engines": {
     "node": ">=0.4.0"
   },
diff --git a/src/index.js b/src/index.js
index 9afaa86fb..8288372be 100644
--- a/src/index.js
+++ b/src/index.js
@@ -37,7 +37,7 @@ export {isIdentifierChar, isIdentifierStart} from "./identifier"
 export {Token} from "./tokenize"
 export {isNewLine, lineBreak, lineBreakG, nonASCIIwhitespace} from "./whitespace"
 
-export const version = "5.6.0"
+export const version = "5.6.1"
 
 // The main exported interface (under `self.acorn` when in the
 // browser) is a `parse` function that takes a code string and