diff --git a/lib/cc/services/slack.rb b/lib/cc/services/slack.rb
index 6ac0576..3a07d43 100644
--- a/lib/cc/services/slack.rb
+++ b/lib/cc/services/slack.rb
@@ -1,6 +1,6 @@
 class CC::Service::Slack < CC::Service
   class Config < CC::Service::Config
-    attribute :url, String,
+    attribute :webhook_url, String,
       label: "Webhook URL",
       description: "The Slack webhook URL you would like message posted to"
 
@@ -42,6 +42,7 @@ def speak(message, options = {})
       body[:channel] = config.channel
     end
 
-    http_post(config.url, body)
+    http.headers['Content-Type']  = 'application/json'
+    http_post(config.webhook_url, body.to_json)
   end
 end
diff --git a/service_test.rb b/service_test.rb
new file mode 100755
index 0000000..827c43d
--- /dev/null
+++ b/service_test.rb
@@ -0,0 +1,17 @@
+#!/usr/bin/env ruby
+#
+# Ad-hoc script for sending the test event to service classes
+#
+###
+require 'cc/services'
+CC::Service.load_services
+
+def test_service(klass, config)
+  service = klass.new(:test, config, { repo_name: "Example" })
+  service.receive
+end
+
+test_service(CC::Service::Slack, {
+  webhook_url: "...",
+  channel: "..."
+})
diff --git a/test/slack_test.rb b/test/slack_test.rb
index f377cbe..c4a93b1 100644
--- a/test/slack_test.rb
+++ b/test/slack_test.rb
@@ -99,7 +99,7 @@ def test_multiple_vulnerabilities
 
   def assert_slack_receives(event_name, emoji, event_data, expected_body)
     @stubs.post '/token' do |env|
-      body = Hash[URI.decode_www_form(env[:body])]
+      body = JSON.parse(env[:body])
       assert_equal "Code Climate", body["username"]
       assert_equal emoji, body["icon_emoji"] # may be nil
       assert_equal expected_body, body["text"]
@@ -109,7 +109,7 @@ def assert_slack_receives(event_name, emoji, event_data, expected_body)
     receive(
       CC::Service::Slack,
       event_name,
-      { url: "http://api.slack.com/token", channel: "#general" },
+      { webhook_url: "http://api.slack.com/token", channel: "#general" },
       event_data
     )
   end