diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c33708..259339b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  ### Changes
 - Fix symbol json encoding breaking compatibility with some gems
 
+### Added
+- Added `event_data` property when sending event
+
 ## [0.4.0] - 2019-03-25
 ### Added
 - Calling `#dispatch` on tasks now allows to process tasks asynchronously
diff --git a/lib/zenaton/client.rb b/lib/zenaton/client.rb
index 56cdfdd..2f43ab8 100644
--- a/lib/zenaton/client.rb
+++ b/lib/zenaton/client.rb
@@ -33,8 +33,9 @@ class Client
 
     PROG = 'Ruby' # The current programming language
 
-    EVENT_INPUT = 'event_input' # Parameter name for event data
+    EVENT_INPUT = 'event_input' # Parameter name for event input
     EVENT_NAME = 'event_name' # Parameter name for event name
+    EVENT_DATA = 'event_data' # Parameter name for event data
 
     WORKFLOW_KILL = 'kill' # Worker update mode to stop a worker
     WORKFLOW_PAUSE = 'pause' # Worker udpate mode to pause a worker
@@ -174,7 +175,8 @@ def send_event(workflow_name, custom_id, event)
         ATTR_NAME => workflow_name,
         ATTR_ID => custom_id,
         EVENT_NAME => event.class.name,
-        EVENT_INPUT => @serializer.encode(@properties.from(event))
+        EVENT_INPUT => @serializer.encode(@properties.from(event)),
+        EVENT_DATA => @serializer.encode(event)
       }
       @http.post(send_event_url, body)
     end
diff --git a/spec/zenaton/client_spec.rb b/spec/zenaton/client_spec.rb
index 3ee17d7..fadcad3 100644
--- a/spec/zenaton/client_spec.rb
+++ b/spec/zenaton/client_spec.rb
@@ -418,7 +418,14 @@
         'name' => 'MyWorkflow',
         'custom_id' => 'MyCustomId',
         'event_name' => 'FakeEvent',
-        'event_input' => { 'o' => '@zenaton#0', 's' => [{ 'a' => {} }] }.to_json
+        'event_input' => {
+          'o' => '@zenaton#0',
+          's' => [{ 'a' => {} }]
+        }.to_json,
+        'event_data' => {
+          'o' => '@zenaton#0',
+          's' => [{ 'n' => 'FakeEvent', 'p' => {} }]
+        }.to_json
       }
     end