diff --git a/HISTORY b/HISTORY
index ff2a0d0..67e3c3f 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,3 +1,8 @@
+=== 4.0.0 2019-05-15
+- Fix URL encoding
+- Propagate exception in Client.track
+- Add Circle build
+
 === 3.3.0 2018-07-31
 - Add support for rescore_user and get_user_score APIs
 
diff --git a/lib/sift/version.rb b/lib/sift/version.rb
index b904c3d..9ac8542 100644
--- a/lib/sift/version.rb
+++ b/lib/sift/version.rb
@@ -1,4 +1,4 @@
 module Sift
-  VERSION = "3.3.0"
+  VERSION = "4.0.0"
   API_VERSION = "205"
 end