diff --git a/Gemfile b/Gemfile
index 105270f7..97dd488f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -31,16 +31,6 @@ else
   gem 'sqlite3', '~> 1.4', :platform => [:ruby, :mswin, :mingw] # rubocop:disable Bundler/DuplicatedGem
 end
 
-unless is_jruby
-  if RUBY_VERSION >= '2.5'
-    gem 'oj'
-  elsif RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1' # rubocop:disable Bundler/DuplicatedGem
-  else
-    gem 'oj', '~> 2.12.14' # rubocop:disable Bundler/DuplicatedGem
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails30.gemfile b/gemfiles/rails30.gemfile
index 89c95a67..a7abfd2f 100644
--- a/gemfiles/rails30.gemfile
+++ b/gemfiles/rails30.gemfile
@@ -20,14 +20,6 @@ gem 'hitimes', '< 1.2.2'
 gem 'rake', '< 11'
 gem 'rspec-rails', '>= 2.14.0'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails31.gemfile b/gemfiles/rails31.gemfile
index e55da050..d762cfda 100644
--- a/gemfiles/rails31.gemfile
+++ b/gemfiles/rails31.gemfile
@@ -19,14 +19,6 @@ gem 'rails', '3.1.12'
 gem 'rspec-rails', '~> 3.4'
 gem 'rake'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails32.gemfile b/gemfiles/rails32.gemfile
index 6d1996d4..f2859576 100644
--- a/gemfiles/rails32.gemfile
+++ b/gemfiles/rails32.gemfile
@@ -21,14 +21,6 @@ gem 'sqlite3', '< 1.4.0', :platform => [:ruby, :mswin, :mingw]
 # Please see https://github.com/rspec/rspec-rails/issues/1273
 gem 'test-unit'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails40.gemfile b/gemfiles/rails40.gemfile
index 496655a5..bb26d1fa 100644
--- a/gemfiles/rails40.gemfile
+++ b/gemfiles/rails40.gemfile
@@ -21,14 +21,6 @@ gem 'sqlite3', '< 1.4.0', :platform => [:ruby, :mswin, :mingw]
 # Please see https://github.com/rspec/rspec-rails/issues/1273
 gem 'test-unit'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails41.gemfile b/gemfiles/rails41.gemfile
index 478b60ed..5a9ce132 100644
--- a/gemfiles/rails41.gemfile
+++ b/gemfiles/rails41.gemfile
@@ -19,14 +19,6 @@ gem 'rake'
 gem 'rspec-rails', '~> 3.4'
 gem 'sqlite3', '< 1.4.0', :platform => [:ruby, :mswin, :mingw]
 
-unless is_jruby
-  if RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails42.gemfile b/gemfiles/rails42.gemfile
index 0c339ad3..25905178 100644
--- a/gemfiles/rails42.gemfile
+++ b/gemfiles/rails42.gemfile
@@ -27,16 +27,6 @@ platforms :rbx do
   gem 'rubysl', '~> 2.0' unless RUBY_VERSION.start_with?('1')
 end
 
-unless is_jruby
-  if RUBY_VERSION >= '2.5'
-    gem 'oj'
-  elsif RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 if RUBY_VERSION < '2.2.2'
   gem 'sidekiq', '~> 2.13.0'
 else
diff --git a/gemfiles/rails50.gemfile b/gemfiles/rails50.gemfile
index 9b36d66f..e8c3b0eb 100644
--- a/gemfiles/rails50.gemfile
+++ b/gemfiles/rails50.gemfile
@@ -27,16 +27,6 @@ gem 'rake'
 
 gem 'sidekiq', '>= 2.13.0'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.5'
-    gem 'oj'
-  elsif RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 platforms :rbx do
   gem 'minitest'
   gem 'racc'
diff --git a/gemfiles/rails51.gemfile b/gemfiles/rails51.gemfile
index c84a6566..436b161d 100644
--- a/gemfiles/rails51.gemfile
+++ b/gemfiles/rails51.gemfile
@@ -27,16 +27,6 @@ gem 'rake'
 
 gem 'sidekiq', '>= 2.13.0'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.5'
-    gem 'oj'
-  elsif RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 platforms :rbx do
   gem 'minitest'
   gem 'racc'
diff --git a/gemfiles/rails52.gemfile b/gemfiles/rails52.gemfile
index 872281b6..952d5de2 100644
--- a/gemfiles/rails52.gemfile
+++ b/gemfiles/rails52.gemfile
@@ -25,16 +25,6 @@ gem 'rspec-mocks', '~> 3.8.0'
 
 gem 'rake'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.5'
-    gem 'oj'
-  elsif RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 gem 'sidekiq', '>= 2.13.0'
 
 platforms :rbx do
diff --git a/gemfiles/rails60.gemfile b/gemfiles/rails60.gemfile
index 302fb062..2719e74a 100644
--- a/gemfiles/rails60.gemfile
+++ b/gemfiles/rails60.gemfile
@@ -27,16 +27,6 @@ gem 'rspec-rails', :git => 'https://github.com/rspec/rspec-rails', :ref => 'v4.0
 
 gem 'rake'
 
-unless is_jruby
-  if RUBY_VERSION >= '2.5'
-    gem 'oj'
-  elsif RUBY_VERSION >= '2.4.0'
-    gem 'oj', '~> 2.16.1'
-  else
-    gem 'oj', '~> 2.12.14'
-  end
-end
-
 gem 'sidekiq', '>= 2.13.0'
 
 platforms :rbx do
diff --git a/lib/rollbar/json.rb b/lib/rollbar/json.rb
index f612abdf..6081ec31 100644
--- a/lib/rollbar/json.rb
+++ b/lib/rollbar/json.rb
@@ -1,13 +1,5 @@
-require 'multi_json'
-require 'rollbar/json/oj'
-require 'rollbar/json/default'
 require 'rollbar/language_support'
 
-begin
-  require 'oj'
-rescue LoadError
-end
-
 module Rollbar
   module JSON # :nodoc:
     extend self
@@ -15,54 +7,13 @@ module JSON # :nodoc:
     attr_writer :options_module
 
     def dump(object)
-      # `basic_socket` plugin addresses the following issue: https://github.com/rollbar/rollbar-gem/issues/845
       Rollbar.plugins.get('basic_socket').load_scoped!(true) do
-        with_adapter { MultiJson.dump(object, adapter_options) }
+        ::JSON.generate(object)
       end
     end
 
     def load(string)
-      with_adapter { MultiJson.load(string, adapter_options) }
-    end
-
-    def with_adapter(&block)
-      MultiJson.with_adapter(detect_multi_json_adapter, &block)
-    end
-
-    def detect_multi_json_adapter
-      options = {}
-      options[:adapter] = :oj if defined?(::Oj)
-
-      MultiJson.current_adapter(options)
-    end
-
-    def adapter_options
-      options_module.options
-    end
-
-    def options_module
-      @options_module ||= find_options_module
-    end
-
-    def find_options_module
-      module_name = multi_json_adapter_module_name
-
-      if LanguageSupport.const_defined?(Rollbar::JSON, module_name, false)
-        LanguageSupport.const_get(Rollbar::JSON, module_name, false)
-      else
-        Default
-      end
-    end
-
-    # MultiJson adapters have this name structure:
-    # "MultiJson::Adapters::{AdapterModule}"
-    #
-    # Ex: MultiJson::Adapters::Oj
-    # Ex: MultiJson::Adapters::JsonGem
-    #
-    # In this method we just get the last module name.
-    def multi_json_adapter_module_name
-      detect_multi_json_adapter.name[/^MultiJson::Adapters::(.*)$/, 1]
+      ::JSON.parse(string)
     end
   end
 end
diff --git a/lib/rollbar/json/default.rb b/lib/rollbar/json/default.rb
deleted file mode 100644
index d10192eb..00000000
--- a/lib/rollbar/json/default.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-module Rollbar
-  module JSON
-    module Default
-      module_function
-
-      def options
-        {}
-      end
-    end
-  end
-end
diff --git a/lib/rollbar/json/oj.rb b/lib/rollbar/json/oj.rb
deleted file mode 100644
index 42a64073..00000000
--- a/lib/rollbar/json/oj.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-module Rollbar
-  module JSON
-    module Oj
-      module_function
-
-      def options
-        {
-          :mode => :compat,
-          :use_to_json => false,
-          :symbol_keys => false,
-          :circular => false
-        }
-      end
-    end
-  end
-end
diff --git a/lib/rollbar/plugins/basic_socket.rb b/lib/rollbar/plugins/basic_socket.rb
index 91855286..5cb16f84 100644
--- a/lib/rollbar/plugins/basic_socket.rb
+++ b/lib/rollbar/plugins/basic_socket.rb
@@ -6,7 +6,7 @@
   # Needed to avoid active_support (< 4.1.0) bug serializing JSONs
   dependency do
     defined?(ActiveSupport::VERSION::STRING) &&
-      Gem::Version.new(ActiveSupport::VERSION::STRING) < Gem::Version.new('5.2.0')
+      Gem::Version.new(ActiveSupport::VERSION::STRING) < Gem::Version.new('4.1.0')
   end
 
   execute do
diff --git a/lib/rollbar/util/hash.rb b/lib/rollbar/util/hash.rb
index 8bf2925b..336c6200 100644
--- a/lib/rollbar/util/hash.rb
+++ b/lib/rollbar/util/hash.rb
@@ -5,6 +5,7 @@ def self.deep_stringify_keys(hash, seen = {})
         return if seen[hash.object_id]
 
         seen[hash.object_id] = true
+        replace_seen_children(hash, seen)
 
         hash.reduce({}) do |h, (key, value)|
           h[key.to_s] = map_value(value, :deep_stringify_keys, seen)
@@ -22,12 +23,26 @@ def self.map_value(thing, meth, seen)
             thing
           else
             seen[thing.object_id] = true
+            replace_seen_children(thing, seen)
             thing.map { |v| map_value(v, meth, seen) }
           end
         else
           thing
         end
       end
+
+      def self.replace_seen_children(thing, seen)
+        case thing
+        when ::Hash
+          thing.keys.each do |key|
+            thing[key] = "removed circular reference: #{thing[key]}" if seen[thing[key].object_id]
+          end
+        when Array
+          thing.each_with_index do |_, i|
+            thing[i] = "removed circular reference: #{thing[i]}" if seen[thing[i].object_id]
+          end
+        end
+      end
     end
   end
 end
diff --git a/rollbar.gemspec b/rollbar.gemspec
index d3f567f6..15ce6b28 100644
--- a/rollbar.gemspec
+++ b/rollbar.gemspec
@@ -18,8 +18,6 @@ Gem::Specification.new do |gem|
   gem.required_ruby_version = '>= 1.9.3'
   gem.version = Rollbar::VERSION
 
-  gem.add_runtime_dependency 'multi_json'
-
   if gem.respond_to?(:metadata)
     gem.metadata['changelog_uri'] = 'https://github.com/rollbar/rollbar-gem/releases'
     gem.metadata['source_code_uri'] = 'https://github.com/rollbar/rollbar-gem'
diff --git a/spec/rollbar/item_spec.rb b/spec/rollbar/item_spec.rb
index e8cf66be..9dc1ed2d 100644
--- a/spec/rollbar/item_spec.rb
+++ b/spec/rollbar/item_spec.rb
@@ -687,17 +687,34 @@ def as_json(*)
       end
       let(:item) { Rollbar::Item.build_with(payload) }
 
-      it 'fails in ActiveSupport with stack too deep' do
+      it "doesn't fail in ActiveSupport >= 4.1" do
         begin
           _json = item.dump
-        rescue NoMemoryError, SystemStackError, Java::JavaLang::StackOverflowError
+
+        # If you get an uninitialized constant "Java" error, it just means an unexpected exception
+        # occurred (i.e. one not in the below list) and caused Java::JavaLang::StackOverflowError.
+        # If the test case is working correctly, this shouldn't happen ang the Java error type
+        # will only be evaluated on JRuby builds.
+        rescue NoMemoryError,
+               SystemStackError,
+               ActiveSupport::JSON::Encoding::CircularReferenceError,
+               Java::JavaLang::StackOverflowError
+
+          # If ActiveSupport is invoked, we'll end up here.
           # Item#dump fails with SystemStackError (ActiveSupport > 4.0)
           # or NoMemoryError (ActiveSupport <= 4.0) which, as system exceptions
           # not a StandardError, cannot be tested by `expect().to raise_error`
           error = :SystemError
         end
 
-        expect(error).to be_eql(:SystemError)
+        if Gem::Version.new(ActiveSupport::VERSION::STRING) >= Gem::Version.new('4.1.0')
+          expect(error).not_to be_eql(:SystemError)
+        else
+          # This ActiveSupport is vulnerable to circular reference errors, and is
+          # virtually impossible to correct, because these versions of AS even hook into
+          # core Ruby JSON.
+          expect(error).to be_eql(:SystemError)
+        end
       end
     end
 
diff --git a/spec/rollbar/json/oj_spec.rb b/spec/rollbar/json/oj_spec.rb
deleted file mode 100644
index 936ec8f9..00000000
--- a/spec/rollbar/json/oj_spec.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-require 'spec_helper'
-
-require 'rollbar/json/oj'
-
-describe Rollbar::JSON::Oj do
-  let(:options) do
-    {
-      :mode => :compat,
-      :use_to_json => false,
-      :symbol_keys => false,
-      :circular => false
-    }
-  end
-
-  it 'returns correct options' do
-    expect(described_class.options).to be_eql(options)
-  end
-end
diff --git a/spec/rollbar/json_spec.rb b/spec/rollbar/json_spec.rb
index 0423db77..2007d303 100644
--- a/spec/rollbar/json_spec.rb
+++ b/spec/rollbar/json_spec.rb
@@ -1,122 +1,26 @@
 require 'spec_helper'
 
-require 'multi_json'
 require 'rollbar/json'
 require 'rollbar/configuration'
 
-class Rollbar::JSON::MockAdapter
-  def self.options
-    { 'mock' => 'adapter' }
-  end
-end
-
-module MultiJson
-  module Adapters
-    module MockAdapter
-    end
-  end
-end
-
-module MultiJson
-  module Adapters
-    module MissingCustomOptions
-    end
-  end
-end
-
-module MissingCustomOptions
-  # Consider the fact that there's MultiJson::Adapters::Yajl but not
-  # Rollbar::JSON::Yajl, it should not look for ::Yajl but only
-  # Rollbar::JSON::Yajl.
-end
-
 describe Rollbar::JSON do
   let(:payload) do
     { :foo => :bar }
   end
-  let(:adapter_options) { { 'option' => 'value' } }
 
   describe '.dump' do
-    before do
-      allow(described_class).to receive(:adapter_options).and_return(adapter_options)
-    end
-
-    it 'calls MultiJson.dump' do
-      expect(::MultiJson).to receive(:dump).once.with(payload, adapter_options)
+    it 'calls JSON.generate' do
+      expect(::JSON).to receive(:generate).once.with(payload)
 
       described_class.dump(payload)
     end
-
-    context 'with basic_socket plugin unloadable' do
-      before do
-        Rollbar.configuration.disable_core_monkey_patch = true
-      end
-
-      it 'still calls MultiJson.dump' do
-        expect(::MultiJson).to receive(:dump).once.with(payload, adapter_options)
-
-        described_class.dump(payload)
-      end
-    end
   end
 
   describe '.load' do
-    before do
-      allow(described_class).to receive(:adapter_options).and_return(adapter_options)
-    end
-
-    it 'calls MultiJson.load' do
-      expect(::MultiJson).to receive(:load).once.with(payload, adapter_options)
+    it 'calls JSON.parse' do
+      expect(::JSON).to receive(:parse).once.with(payload)
 
       described_class.load(payload)
     end
   end
-
-  describe '.with_adapter' do
-    let(:object) { double(:foo => 'bar') }
-    let(:callback) do
-      proc { object.foo }
-    end
-    let(:adapter) { described_class.detect_multi_json_adapter }
-
-    it 'calls mock.something with an adapter' do
-      expect(MultiJson).to receive(:with_adapter).with(adapter).and_call_original
-      expect(object).to receive(:foo).once
-
-      described_class.with_adapter(&callback)
-    end
-  end
-
-  describe '.adapter_options' do
-    it 'calls .options in adapter module' do
-      expect(described_class.options_module).to receive(:options)
-
-      described_class.adapter_options
-    end
-  end
-
-  describe '.options_module' do
-    before do
-      described_class.options_module = nil
-      allow(MultiJson).to receive(:current_adapter).and_return(multi_json_module)
-    end
-
-    context 'with a defined rollbar adapter' do
-      let(:multi_json_module) { MultiJson::Adapters::MockAdapter }
-      let(:expected_adapter) { Rollbar::JSON::MockAdapter }
-
-      it 'returns the correct options' do
-        expect(described_class.options_module).to be(expected_adapter)
-      end
-    end
-
-    context 'without a defined rollbar adapter' do
-      let(:multi_json_module) { MultiJson::Adapters::MissingCustomOptions }
-      let(:expected_adapter) { Rollbar::JSON::Default }
-
-      it 'returns the correct options' do
-        expect(described_class.options_module).to be(expected_adapter)
-      end
-    end
-  end
 end
diff --git a/spec/rollbar/plugins/basic_socket_spec.rb b/spec/rollbar/plugins/basic_socket_spec.rb
index 286a18f3..f1eedc96 100644
--- a/spec/rollbar/plugins/basic_socket_spec.rb
+++ b/spec/rollbar/plugins/basic_socket_spec.rb
@@ -34,8 +34,8 @@
     context 'with core monkey patching enabled' do
       before { subject.configuration.disable_core_monkey_patch = false }
 
-      if Gem::Version.new(ActiveSupport::VERSION::STRING) < Gem::Version.new('5.2.0')
-        context 'using active_support < 5.2' do
+      if Gem::Version.new(ActiveSupport::VERSION::STRING) < Gem::Version.new('4.1.0')
+        context 'using active_support < 4.1' do
           it 'changes implementation of ::BasicSocket#as_json temporarily' do
             original_implementation = BasicSocket.
               public_instance_method(:as_json).
@@ -54,7 +54,7 @@
           end
         end
       else
-        context 'using active_support >= 5.2' do
+        context 'using active_support >= 4.1' do
           context 'when called as transparent' do
             it 'executes provided block even when dependencies are unmet' do
               result = false
@@ -72,8 +72,8 @@
   end
 
   describe '#load!' do
-    if Gem::Version.new(ActiveSupport::VERSION::STRING) < Gem::Version.new('5.2.0')
-      context 'using active_support < 5.2' do
+    if Gem::Version.new(ActiveSupport::VERSION::STRING) < Gem::Version.new('4.1.0')
+      context 'using active_support < 4.1' do
         context 'with core monkey patching enabled' do
           before { subject.configuration.disable_core_monkey_patch = false }
 
@@ -103,7 +103,7 @@
         end
       end
     else
-      context 'using active_support >= 5.2' do
+      context 'using active_support >= 4.1' do
         it_should_behave_like 'unloadable'
       end
     end
diff --git a/spec/rollbar/plugins/rack_spec.rb b/spec/rollbar/plugins/rack_spec.rb
index 0adfc2a2..61b96468 100644
--- a/spec/rollbar/plugins/rack_spec.rb
+++ b/spec/rollbar/plugins/rack_spec.rb
@@ -89,11 +89,11 @@ class RackMockError < RuntimeError; end
   end
 
   context 'with not array or hash POST parameters' do
-    let(:params) { 1000 }
+    let(:params) { 'test string' }
 
     it 'sends a body.multi key in params' do
       expect do
-        request.post('/will_crash', :input => params.to_json, 'CONTENT_TYPE' => 'application/json')
+        request.post('/will_crash', :input => params, 'CONTENT_TYPE' => 'application/json')
       end.to raise_error(exception)
 
       reported_body = Rollbar.last_report[:request][:body]
diff --git a/spec/rollbar/util/hash_spec.rb b/spec/rollbar/util/hash_spec.rb
index ee83f95e..1456b82e 100644
--- a/spec/rollbar/util/hash_spec.rb
+++ b/spec/rollbar/util/hash_spec.rb
@@ -19,4 +19,22 @@
     expect(new_hash['bar']['foo']).to be_eql('bar')
     expect(new_hash['bar']['bar'][0]['foo']).to be_eql('bar')
   end
+
+  it 'should replace circular references' do
+    a = { :foo => 'bar' }
+    b = { :a => a }
+    c = { :b => b }
+    a[:c] = c # Introduces a cycle
+
+    array1 = %w[a b]
+    array2 = ['c', 'd', array1]
+    a[:array] = array1
+
+    array1 << array2 # Introduces a cycle
+
+    new_hash = described_class.deep_stringify_keys(a)
+
+    expect(new_hash['c']['b']['a'].include?('removed circular reference')).to be_truthy
+    expect(new_hash['array'][2][2].include?('removed circular reference')).to be_truthy
+  end
 end
diff --git a/spec/rollbar_spec.rb b/spec/rollbar_spec.rb
index 885fbe67..cca2abdc 100644
--- a/spec/rollbar_spec.rb
+++ b/spec/rollbar_spec.rb
@@ -1128,22 +1128,13 @@ def backtrace
       a = { :foo => 'bar' }
       b = { :a => a }
       c = { :b => b }
-      a[:c] = c
+      a[:c] = c # Introduces a cycle
 
       array1 = %w[a b]
-      _array2 = ['c', 'd', array1]
+      array2 = ['c', 'd', array1]
       a[:array] = array1
 
-      # The line below will introduce a cycle in the array, which the rollbar code can handle.
-      # However, both OJ and ActiveSupport `as_json` crash on this when serializing the payload.
-      # We could do without OJ, but it's a moot point because of the ActiveSupport issue.
-      # The gemspec currently uses multi_json to give the user as much control as possible over
-      # choice of JSON serializer. We should continue to allow this flexibility unless it is
-      # determined that cycles of arrays directly referencing arrays (without other objects
-      # in between) must be supported. Then in that case, an appropriate serializer should
-      # be added to the gemspec.
-      #
-      # array1 << array2
+      array1 << array2 # Introduces a cycle
 
       expect(logger_mock).to_not receive(:error).with(
         /\[Rollbar\] Reporting internal error encountered while sending data to Rollbar./