diff --git a/CHANGELOG b/CHANGELOG
index bf7d79fe8f2b54752a8d460224dd9459541fd53a..da700eca24229ad11c6919ec01e5213589252b26 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,6 +5,12 @@
 Changelog
 ================================================================================
 
+Release 3.3.1
+--------------------------------------------------------------------------------
+
+* Bugfix release: Updates OpenStructure dependency to 2.5.0 and fixes issues
+  with Singularity container.
+
 Release 3.3.0
 --------------------------------------------------------------------------------