diff --git a/CHANGELOG.md b/CHANGELOG.md
index cda92b0..88da2c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## Changelog
 
+## 0.13.0
+
+* Allows optional args in transforms.
+* Bump `mapnik-reference` dependency to 5.1.x.
+
 ## 0.12.0
 
 * Drop mml2json and xml2js dependency.
diff --git a/package.json b/package.json
index 295d63e..e8aab41 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "carto",
-  "version": "0.12.1",
+  "version": "0.13.0",
   "description": "Mapnik Stylesheet Compiler",
   "url": "https://github.com/mapbox/carto",
   "repository": {