diff --git a/docs/project/changelog.rst b/docs/project/changelog.rst
index d87f4545..264e6e42 100644
--- a/docs/project/changelog.rst
+++ b/docs/project/changelog.rst
@@ -28,7 +28,7 @@ notice.
 12.0
 ----
 
-*In development*
+*October 21, 2023*
 
 Backwards-incompatible changes
 ..............................
diff --git a/src/websockets/version.py b/src/websockets/version.py
index 3f171b39..d1c99458 100644
--- a/src/websockets/version.py
+++ b/src/websockets/version.py
@@ -18,7 +18,7 @@
 # When tagging a release, set `released = True`.
 # After tagging a release, set `released = False` and increment `tag`.
 
-released = False
+released = True
 
 tag = version = commit = "12.0"