diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07f6d3f50..496738361 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,13 @@
 Changelog
 =========
 
+## 5.4.0 (02 Oct 2017)
+
+### Enhancements
+
+* Add a one-time warning if the API key is not set
+* Track whether errors were captured automatically and by which middleware
+
 ## 5.3.3 (16 June 2017)
 
 * [Rails] Fix failure to report when encountering objects which throw in `to_s`
diff --git a/VERSION b/VERSION
index 74664af74..8a30e8f94 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.3.3
+5.4.0