diff --git a/CHANGELOG.md b/CHANGELOG.md
index 88a38a3..7ea7fba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## master
 
+## v4.0.0
+
 - [Added] `OPQ.Queue` wraps `:queue` and implements `Enumerable`
 
 ## v3.3.0 [2021-10-12]
diff --git a/mix.exs b/mix.exs
index 8b3f34e..2806ac7 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,7 +2,7 @@ defmodule OPQ.Mixfile do
   use Mix.Project
 
   @source_url "https://github.com/fredwu/crawler"
-  @version "3.3.0"
+  @version "4.0.0"
 
   def project do
     [