diff --git a/app/services/aggregation_client.rb b/app/services/aggregation_client.rb
index afe19be3e..6690a918e 100644
--- a/app/services/aggregation_client.rb
+++ b/app/services/aggregation_client.rb
@@ -8,8 +8,8 @@ class ServerError < ConnectionError; end
   attr_reader :connection
 
   def initialize(adapter=Faraday.default_adapter)
+    @host = ENV.fetch('AGGREGATION_HOST', 'https://aggregation-staging.zooniverse.org')
     @connection = connect!(adapter)
-    @host ||= ENV.fetch('AGGREGATION_HOST', 'http://test.example.com')
   end
 
   def connect!(adapter)
@@ -24,7 +24,7 @@ def send_aggregation_request(project_id, workflow_id, user_id)
     params = { project_id: project_id, workflow_id: workflow_id, user_id: user_id }
 
     request(:post, '/run_aggregation') do |req|
-      req.body = params.to_json
+      req.body = params
     end
   end
 
diff --git a/kubernetes/deployment-production.tmpl b/kubernetes/deployment-production.tmpl
index da6439a50..5c39f42e0 100644
--- a/kubernetes/deployment-production.tmpl
+++ b/kubernetes/deployment-production.tmpl
@@ -120,6 +120,7 @@ data:
   TALK_API_USER: '1'
   TALK_API_APPLICATION: '1'
   USER_SUBJECT_LIMIT: '10000'
+  AGGREGATION_HOST: http://aggregation-caesar/
 ---
 apiVersion: apps/v1
 kind: Deployment
diff --git a/kubernetes/deployment-staging.tmpl b/kubernetes/deployment-staging.tmpl
index 8ae7e3bbd..4cf3ebd90 100644
--- a/kubernetes/deployment-staging.tmpl
+++ b/kubernetes/deployment-staging.tmpl
@@ -109,6 +109,7 @@ data:
   TALK_API_USER: '1'
   TALK_API_APPLICATION: '1'
   USER_SUBJECT_LIMIT: '100'
+  AGGREGATION_HOST: http://aggregation-staging-app/
 ---
 apiVersion: apps/v1
 kind: Deployment