diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 3b07edf..f80776a 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.13.1"
+  ".": "0.13.2"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98a325b..413f297 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 0.13.2 (2026-06-17)
+
+Full Changelog: [v0.13.1...v0.13.2](https://github.com/openlayer-ai/openlayer-ruby/compare/v0.13.1...v0.13.2)
+
+### Bug Fixes
+
+* **client:** send content-type header for requests with an omitted optional body ([07287c7](https://github.com/openlayer-ai/openlayer-ruby/commit/07287c7484e72bf8c389eabd167e4a25ed0fd6d5))
+
 ## 0.13.1 (2026-05-14)
 
 Full Changelog: [v0.13.0...v0.13.1](https://github.com/openlayer-ai/openlayer-ruby/compare/v0.13.0...v0.13.1)
diff --git a/Gemfile.lock b/Gemfile.lock
index 33c8799..b792c9f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,7 +11,7 @@ GIT
 PATH
   remote: .
   specs:
-    openlayer (0.13.1)
+    openlayer (0.13.2)
       cgi
       connection_pool
 
diff --git a/README.md b/README.md
index cb226a0..213615c 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ To use this gem, install via Bundler by adding the following to your application
 <!-- x-release-please-start-version -->
 
 ```ruby
-gem "openlayer", "~> 0.13.1"
+gem "openlayer", "~> 0.13.2"
 ```
 
 <!-- x-release-please-end -->
diff --git a/lib/openlayer/internal/transport/base_client.rb b/lib/openlayer/internal/transport/base_client.rb
index d8fd5fc..c67c892 100644
--- a/lib/openlayer/internal/transport/base_client.rb
+++ b/lib/openlayer/internal/transport/base_client.rb
@@ -306,7 +306,10 @@ def initialize(
               Openlayer::Internal::Util.deep_merge(*[req[:body], opts[:extra_body]].compact)
             end
 
-          headers.delete("content-type") if body.nil?
+          # Generated methods always pass `req[:body]` for operations that define a
+          # request body, so only elide the content-type header when the operation
+          # has no body at all, not when an optional body param was omitted.
+          headers.delete("content-type") if body.nil? && !req.key?(:body)
 
           url = Openlayer::Internal::Util.join_parsed_uri(
             @base_url_components,
diff --git a/lib/openlayer/version.rb b/lib/openlayer/version.rb
index 102b706..001f902 100644
--- a/lib/openlayer/version.rb
+++ b/lib/openlayer/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Openlayer
-  VERSION = "0.13.1"
+  VERSION = "0.13.2"
 end