diff --git a/Changelog.md b/Changelog.md
index 473cc69..4119790 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 4.0.0
+
+- Turned all NamedTuples into Dataclasses. Even if this is technically a breaking change
+  probably not much source code is actually affected as constructing instances still behaves
+  the same.
+
 ## 3.5.1
 
 - Fix failing serialization of Prompt-based Documents in QA requests.
diff --git a/aleph_alpha_client/version.py b/aleph_alpha_client/version.py
index 0c11bab..ce1305b 100644
--- a/aleph_alpha_client/version.py
+++ b/aleph_alpha_client/version.py
@@ -1 +1 @@
-__version__ = "3.5.1"
+__version__ = "4.0.0"