diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40d29452..327dd1c0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ### 0.7.1 (Next)
 
 * Your contribution here.
+* [#69](https://github.com/dblock/slack-ruby-client/issues/69): Add attachments support for `Slack::Web::Api::Endpoints::Chat.chat_update` - [@nicka](https://github.com/nicka).
 
 ### 0.7.0 (3/6/2016)
 
@@ -95,4 +96,3 @@
 ### 0.1.0 (7/25/2015)
 
 * Initial public release with Web and RealTime Messaging API support - [@dblock](https://github.com/dblock).
-
diff --git a/lib/slack/web/api/endpoints/chat.rb b/lib/slack/web/api/endpoints/chat.rb
index 0db7e672..1c3b2eeb 100644
--- a/lib/slack/web/api/endpoints/chat.rb
+++ b/lib/slack/web/api/endpoints/chat.rb
@@ -82,8 +82,14 @@ def chat_postMessage(options = {})
           def chat_update(options = {})
             throw ArgumentError.new('Required arguments :ts missing') if options[:ts].nil?
             throw ArgumentError.new('Required arguments :channel missing') if options[:channel].nil?
-            throw ArgumentError.new('Required arguments :text missing') if options[:text].nil?
+            throw ArgumentError.new('Required arguments :text or :attachments missing') if options[:text].nil? && options[:attachments].nil?
             options = options.merge(channel: channels_id(options)['channel']['id']) if options[:channel]
+            # attachments must be passed as an encoded JSON string
+            if options.key?(:attachments)
+              attachments = options[:attachments]
+              attachments = JSON.dump(attachments) unless attachments.is_a?(String)
+              options = options.merge(attachments: attachments)
+            end
             post('chat.update', options)
           end
         end
diff --git a/lib/slack/web/api/patches/chat.3.update-attachments-support.patch b/lib/slack/web/api/patches/chat.3.update-attachments-support.patch
new file mode 100644
index 00000000..9f06de1f
--- /dev/null
+++ b/lib/slack/web/api/patches/chat.3.update-attachments-support.patch
@@ -0,0 +1,20 @@
+diff --git a/lib/slack/web/api/endpoints/chat.rb b/lib/slack/web/api/endpoints/chat.rb
+index 0db7e67..1c3b2ee 100644
+--- a/lib/slack/web/api/endpoints/chat.rb
++++ b/lib/slack/web/api/endpoints/chat.rb
+@@ -82,8 +82,14 @@ module Slack
+           def chat_update(options = {})
+             throw ArgumentError.new('Required arguments :ts missing') if options[:ts].nil?
+             throw ArgumentError.new('Required arguments :channel missing') if options[:channel].nil?
+-            throw ArgumentError.new('Required arguments :text missing') if options[:text].nil?
++            throw ArgumentError.new('Required arguments :text or :attachments missing') if options[:text].nil? && options[:attachments].nil?
+             options = options.merge(channel: channels_id(options)['channel']['id']) if options[:channel]
++            # attachments must be passed as an encoded JSON string
++            if options.key?(:attachments)
++              attachments = options[:attachments]
++              attachments = JSON.dump(attachments) unless attachments.is_a?(String)
++              options = options.merge(attachments: attachments)
++            end
+             post('chat.update', options)
+           end
+         end
diff --git a/slack-ruby-client.gemspec b/slack-ruby-client.gemspec
index cb6e58d7..9a4884b5 100644
--- a/slack-ruby-client.gemspec
+++ b/slack-ruby-client.gemspec
@@ -25,7 +25,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'hashie'
   s.add_development_dependency 'erubis'
   s.add_development_dependency 'json-schema'
-  s.add_development_dependency 'rake'
+  s.add_development_dependency 'rake', '~> 10'
   s.add_development_dependency 'rspec'
   s.add_development_dependency 'vcr'
   s.add_development_dependency 'webmock'
diff --git a/spec/slack/web/api/endpoints/custom_specs/chat_spec.rb b/spec/slack/web/api/endpoints/custom_specs/chat_spec.rb
index a4544fbd..f4f46385 100644
--- a/spec/slack/web/api/endpoints/custom_specs/chat_spec.rb
+++ b/spec/slack/web/api/endpoints/custom_specs/chat_spec.rb
@@ -30,4 +30,40 @@
       end
     end
   end
+
+  context 'chat_update' do
+    let(:ts) { '1405894322.002768' }
+    it 'automatically converts attachments into JSON' do
+      expect(client).to receive(:post).with(
+        'chat.update',
+        attachments: '[]',
+        channel: 'channel',
+        text: 'text',
+        ts: ts
+      )
+      client.chat_update(attachments: [], channel: 'channel', text: 'text', ts: ts)
+    end
+    context 'ts arguments' do
+      it 'requires ts' do
+        expect { client.chat_update(channel: 'channel') }.to raise_error ArgumentError, /Required arguments :ts missing>/
+      end
+    end
+    context 'text and attachment arguments' do
+      it 'requires text or attachments' do
+        expect { client.chat_update(channel: 'channel', ts: ts) }.to raise_error ArgumentError, /Required arguments :text or :attachments missing/
+      end
+      it 'only text' do
+        expect(client).to receive(:post).with('chat.update', hash_including(text: 'text'))
+        expect { client.chat_update(channel: 'channel', text: 'text', ts: ts) }.to_not raise_error
+      end
+      it 'only attachments' do
+        expect(client).to receive(:post).with('chat.update', hash_including(attachments: '[]'))
+        expect { client.chat_update(attachments: [], channel: 'channel', ts: ts) }.to_not raise_error
+      end
+      it 'both text and attachments' do
+        expect(client).to receive(:post).with('chat.update', hash_including(text: 'text', attachments: '[]'))
+        expect { client.chat_update(attachments: [], channel: 'channel', text: 'text', ts: ts) }.to_not raise_error
+      end
+    end
+  end
 end