diff --git a/sentry-ruby/lib/sentry/breadcrumb.rb b/sentry-ruby/lib/sentry/breadcrumb.rb
index 4f2ed3dfe..c20f8cded 100644
--- a/sentry-ruby/lib/sentry/breadcrumb.rb
+++ b/sentry-ruby/lib/sentry/breadcrumb.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'oj'
+
 module Sentry
   class Breadcrumb
     DATA_SERIALIZATION_ERROR_MESSAGE = "[data were removed due to serialization issues]"
@@ -54,7 +56,7 @@ def message=(message)
 
     def serialized_data
       begin
-        ::JSON.parse(::JSON.generate(@data))
+        Oj.load(Oj.dump(@data, mode: :compat), mode: :compat)
       rescue Exception => e
         Sentry.logger.debug(LOGGER_PROGNAME) do
           <<~MSG
diff --git a/sentry-ruby/lib/sentry/client.rb b/sentry-ruby/lib/sentry/client.rb
index 80f1165c8..1d6183032 100644
--- a/sentry-ruby/lib/sentry/client.rb
+++ b/sentry-ruby/lib/sentry/client.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "sentry/transport"
+require 'oj'
 
 module Sentry
   class Client
@@ -201,7 +202,7 @@ def dispatch_async_event(async_block, event, hint)
         end
 
       if async_block.arity == 2
-        hint = JSON.parse(JSON.generate(hint))
+        hint = Oj.load(Oj.dump(hint, mode: :compat), mode: :compat)
         async_block.call(event_hash, hint)
       else
         async_block.call(event_hash)
diff --git a/sentry-ruby/lib/sentry/envelope.rb b/sentry-ruby/lib/sentry/envelope.rb
index 54da999e1..be139f5fb 100644
--- a/sentry-ruby/lib/sentry/envelope.rb
+++ b/sentry-ruby/lib/sentry/envelope.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'oj'
+
 module Sentry
   # @api private
   class Envelope
@@ -19,7 +21,7 @@ def type
       end
 
       def to_s
-        [JSON.generate(@headers), JSON.generate(@payload)].join("\n")
+        [Oj.dump(@headers, mode: :compat), Oj.dump(@payload, mode: :compat)].join("\n")
       end
 
       def serialize
@@ -40,7 +42,7 @@ def serialize
 
       def size_breakdown
         payload.map do |key, value|
-          "#{key}: #{JSON.generate(value).bytesize}"
+          "#{key}: #{Oj.dump(value, mode: :compat).bytesize}"
         end.join(", ")
       end
 
diff --git a/sentry-ruby/lib/sentry/event.rb b/sentry-ruby/lib/sentry/event.rb
index b9f8a58e6..79f984bd0 100644
--- a/sentry-ruby/lib/sentry/event.rb
+++ b/sentry-ruby/lib/sentry/event.rb
@@ -7,6 +7,7 @@
 require 'sentry/utils/real_ip'
 require 'sentry/utils/request_id'
 require 'sentry/utils/custom_inspection'
+require 'oj'
 
 module Sentry
   # This is an abstract class that defines the shared attributes of an event.
@@ -152,7 +153,7 @@ def to_hash
 
     # @return [Hash]
     def to_json_compatible
-      JSON.parse(JSON.generate(to_hash))
+      Oj.load(Oj.dump(to_hash, mode: :compat), mode: :compat)
     end
 
     private
diff --git a/sentry-ruby/lib/sentry/transport.rb b/sentry-ruby/lib/sentry/transport.rb
index cdfc23359..82552c105 100644
--- a/sentry-ruby/lib/sentry/transport.rb
+++ b/sentry-ruby/lib/sentry/transport.rb
@@ -3,6 +3,7 @@
 require "json"
 require "base64"
 require "sentry/envelope"
+require 'oj'
 
 module Sentry
   class Transport
@@ -82,7 +83,7 @@ def serialize_envelope(envelope)
         serialized_items << item
       end
 
-      data = [JSON.generate(envelope.headers), *serialized_results].join("\n") unless serialized_results.empty?
+      data = [Oj.dump(envelope.headers, mode: :compat), *serialized_results].join("\n") unless serialized_results.empty?
 
       [data, serialized_items]
     end
diff --git a/sentry-ruby/sentry-ruby.gemspec b/sentry-ruby/sentry-ruby.gemspec
index 154d7638c..678f72a65 100644
--- a/sentry-ruby/sentry-ruby.gemspec
+++ b/sentry-ruby/sentry-ruby.gemspec
@@ -21,4 +21,5 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_dependency "concurrent-ruby", '~> 1.0', '>= 1.0.2'
+  spec.add_dependency "oj"
 end