diff --git a/README.md b/README.md
index cbfbd0b..62824f7 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,8 @@ If you want to debug a test you should use `gulp test-without-coverage` to run a
 
 ## Change History
 
+- v0.4.0 (2018-04-11)
+    - Introduced `.has(key)` function
 - v0.3.1 (2018-04-11)
     - Fix: Allow reserved object property names to be used as keys
 - v0.3.0 (2016-04-03)
diff --git a/package.json b/package.json
index 9bc61ee..79bf6f1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "two-buckets-memcache",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "description": "Memcache that trades a simplified expiry strategy for a super low resource consumption",
   "keywords": [
     "memcache",