diff --git a/RELEASE.CHANGELOG.md b/RELEASE.CHANGELOG.md
index b9e4f0f..5e10b23 100644
--- a/RELEASE.CHANGELOG.md
+++ b/RELEASE.CHANGELOG.md
@@ -1,3 +1,7 @@
+### October 27, 2026
+`4.2.3`
+- Remove `AWS_Lambda_python3.15` from the preview runtime list so the preview warning is no longer emitted on Python 3.15 ([#236](https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/236)).
+
 ### October 15, 2026
 `4.2.2`
 - Pin the worker process start method to `fork` in multi-concurrent (Lambda Managed Instances) mode instead of inheriting the interpreter default, which changed from `fork` to `forkserver` in Python 3.14. Workers are now direct children of the runtime process on every supported Python version ([#233](https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/233)). No behavior change on Python 3.13 and earlier; no impact on the standard on-demand path.
diff --git a/awslambdaric/__init__.py b/awslambdaric/__init__.py
index 38703a8..b506d1f 100644
--- a/awslambdaric/__init__.py
+++ b/awslambdaric/__init__.py
@@ -2,4 +2,4 @@
 Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 """
 
-__version__ = "4.2.2"
+__version__ = "4.2.3"
diff --git a/awslambdaric/bootstrap.py b/awslambdaric/bootstrap.py
index 9554b39..a5164c7 100644
--- a/awslambdaric/bootstrap.py
+++ b/awslambdaric/bootstrap.py
@@ -478,7 +478,7 @@ def _setup_logging(log_format, log_level, log_sink):
     logger.addHandler(logger_handler)
 
 
-PREVIEW_RUNTIME_ENVS = {"AWS_Lambda_python3.15"}
+PREVIEW_RUNTIME_ENVS = set()
 
 
 def _log_preview_runtime_warning():