diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a8bd97b..ff94779e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Changelog
 
 ### Unreleased
+* Added dependency on `ostruct` gem
 * Enable SDK to reattach large files to messages on retry
 
 ### 6.1.1 / 2024-08-20
diff --git a/nylas.gemspec b/nylas.gemspec
index dfbe8b24..3dffb6ac 100644
--- a/nylas.gemspec
+++ b/nylas.gemspec
@@ -12,6 +12,7 @@ Gem::Specification.new do |gem|
 
   # Runtime dependencies
   gem.add_runtime_dependency "mime-types", "~> 3.5", ">= 3.5.1"
+  gem.add_runtime_dependency "ostruct", "~> 0.6"
   gem.add_runtime_dependency "rest-client", ">= 2.0.0", "< 3.0"
   gem.add_runtime_dependency "yajl-ruby", "~> 1.4.3", ">= 1.2.1"