diff --git a/CHANGELOG.md b/CHANGELOG.md
index 332ba1d515..17babfa9a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 *See the full release notes on the official documentation website: https://www.elastic.co/guide/en/elasticsearch/client/ruby-api/current/release_notes.html*
 
+## 8.18.1 Release notes
+
+- Updates API code to the latest Elasticsearch 8.18 specification.
+- Adds `inference.put_custom` - Configure a custom inference endpoint.
+- Adds `transform.set_upgrade_mode` - Sets a cluster wide upgrade_mode setting that prepares transform indices for an upgrade.
+
 ## 8.18.0 Release notes
 
 ### API
diff --git a/docs/release_notes/818.asciidoc b/docs/release_notes/818.asciidoc
index c03bba4081..6e2743a353 100644
--- a/docs/release_notes/818.asciidoc
+++ b/docs/release_notes/818.asciidoc
@@ -1,6 +1,14 @@
 [[release_notes_8_18]]
 === 8.18 Release notes
 
+[discrete]
+[[release_notes_8_18_1]]
+=== 8.18.1 Release notes
+
+- Updates API code to the latest Elasticsearch 8.18 specification.
+- Adds `inference.put_custom` - Configure a custom inference endpoint.
+- Adds `transform.set_upgrade_mode` - Sets a cluster wide upgrade_mode setting that prepares transform indices for an upgrade.
+
 [discrete]
 [[release_notes_8_18_0]]
 === 8.18.0 Release notes
diff --git a/elasticsearch-api/lib/elasticsearch/api/version.rb b/elasticsearch-api/lib/elasticsearch/api/version.rb
index adfd7a85aa..d41f6e8c57 100644
--- a/elasticsearch-api/lib/elasticsearch/api/version.rb
+++ b/elasticsearch-api/lib/elasticsearch/api/version.rb
@@ -17,6 +17,6 @@
 
 module Elasticsearch
   module API
-    VERSION = '8.18.0'.freeze
+    VERSION = '8.18.1'.freeze
   end
 end
diff --git a/elasticsearch/elasticsearch.gemspec b/elasticsearch/elasticsearch.gemspec
index dd16a0e5f4..b645f81790 100644
--- a/elasticsearch/elasticsearch.gemspec
+++ b/elasticsearch/elasticsearch.gemspec
@@ -46,7 +46,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = '>= 2.5'
 
   s.add_dependency 'elastic-transport', '~> 8.3'
-  s.add_dependency 'elasticsearch-api', '8.18.0'
+  s.add_dependency 'elasticsearch-api', '8.18.1'
 
   s.add_development_dependency 'base64'
   s.add_development_dependency 'bundler'
diff --git a/elasticsearch/lib/elasticsearch/version.rb b/elasticsearch/lib/elasticsearch/version.rb
index 8d7e5e7064..a14e691213 100644
--- a/elasticsearch/lib/elasticsearch/version.rb
+++ b/elasticsearch/lib/elasticsearch/version.rb
@@ -16,5 +16,5 @@
 # under the License.
 
 module Elasticsearch
-  VERSION = '8.18.0'.freeze
+  VERSION = '8.18.1'.freeze
 end