diff --git a/HISTORY.md b/HISTORY.md
index df2cf93..d6a9b27 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,3 +1,7 @@
+## 1.4.0 (May 30, 2018)
+
+- Updated `csstree` to [1.0.0-alpha.29](https://github.com/csstree/csstree/releases/tag/v1.0.0-alpha.29)
+
 ## 1.3.1 (February 19, 2018)
 
 - Updated `csstree` to 1.0.0-alpha.28
diff --git a/package.json b/package.json
index 4812154..7fd0652 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "csstree-validator",
-  "version": "1.3.1",
+  "version": "1.4.0",
   "description": "CSS validator build on csstree",
   "keywords": [
     "css",