diff --git a/README.md b/README.md
index 176277a..e9dca9d 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,9 @@
 [![Gem Version](https://badge.fury.io/rb/tiktoken_ruby.svg)](https://badge.fury.io/rb/tiktoken_ruby)
+
 # tiktoken_ruby
 
 [Tiktoken](https://github.com/openai/tiktoken) is BPE tokenizer from OpenAI used with their GPT models.
-This is a wrapper around it aimed primarily at enabling accurate counts of GPT model tokens used. 
+This is a wrapper around it aimed primarily at enabling accurate counts of GPT model tokens used.
 
 ## Request for maintainers
 
@@ -20,18 +21,19 @@ If bundler is not being used to manage dependencies, install the gem by executin
     $ gem install tiktoken_ruby
 
 ## Usage
+
 Usage should be very similar to the python library. Here's a simple example
 
 Encode and decode text
+
 ```ruby
 require 'tiktoken_ruby'
-
-# note: retrieving an encoding is not currently thread safe until https://github.com/IAPark/tiktoken_ruby/pull/30 is merged
 enc = Tiktoken.get_encoding("cl100k_base")
 enc.decode(enc.encode("hello world")) #=> "hello world"
 ```
 
 Encoders can also be retrieved by model name
+
 ```ruby
 require 'tiktoken_ruby'
 
@@ -59,7 +61,6 @@ bundle exec rake compile
 bundle exec rake spec
 ```
 
-
 ## License
 
 The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
diff --git a/lib/tiktoken_ruby/encoding.rb b/lib/tiktoken_ruby/encoding.rb
index 4bee10d..21cd70d 100644
--- a/lib/tiktoken_ruby/encoding.rb
+++ b/lib/tiktoken_ruby/encoding.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class Tiktoken::Encoding
+  CACHE_MUTEX = Mutex.new
+
   attr_reader :name
 
   # This returns a new Tiktoken::Encoding instance for the requested encoding
@@ -15,8 +17,10 @@ def self.for_name(encoding)
   # @param encoding [Symbol] The name of the encoding to load
   # @return [Tiktoken::Encoding] The encoding instance
   def self.for_name_cached(encoding)
-    @encodings ||= {}
-    @encodings[encoding.to_sym] ||= Tiktoken::Encoding.for_name(encoding)
+    CACHE_MUTEX.synchronize do
+      @encodings ||= {}
+      @encodings[encoding.to_sym] ||= Tiktoken::Encoding.for_name(encoding)
+    end
   end
 
   # Encodes the text as a list of integer tokens. This encoding will encode special non text tokens