diff --git a/app/services/ejabberd_api_client.rb b/app/services/ejabberd_api_client.rb
index ddce590..65b3795 100644
--- a/app/services/ejabberd_api_client.rb
+++ b/app/services/ejabberd_api_client.rb
@@ -4,7 +4,7 @@ class EjabberdApiClient
   end
 
   def post(endpoint, payload)
-    res = Faraday.post("#{@base_url}/#{endpoint}", payload,
+    res = Faraday.post("#{@base_url}/#{endpoint}", payload.to_json,
                        "Content-Type" => "application/json")
 
     if res.status != 200
diff --git a/spec/services/create_account_spec.rb b/spec/services/create_account_spec.rb
index 2808836..c6e74d5 100644
--- a/spec/services/create_account_spec.rb
+++ b/spec/services/create_account_spec.rb
@@ -90,17 +90,9 @@ RSpec.describe CreateAccount, type: :model do
       service.send(:exchange_xmpp_contacts)
 
       expect(WebMock).to have_requested(:post, "http://xmpp.example.com/api/add_rosteritem")
-        .with { |req| req.body == {
-          localuser: "isaacnewton", localhost: "kosmos.org",
-          user: "willherschel", host: "kosmos.org",
-          nick: "willherschel", group: "Friends", subs: "both"
-        }}
+        .with { |req| req.body == '{"localuser":"isaacnewton","localhost":"kosmos.org","user":"willherschel","host":"kosmos.org","nick":"willherschel","group":"Friends","subs":"both"}' }
       expect(WebMock).to have_requested(:post, "http://xmpp.example.com/api/add_rosteritem")
-        .with { |req| req.body == {
-          localuser: "willherschel", localhost: "kosmos.org",
-          user: "isaacnewton", host: "kosmos.org",
-          nick: "isaacnewton", group: "Friends", subs: "both"
-        }}
+        .with { |req| req.body == '{"localuser":"willherschel","localhost":"kosmos.org","user":"isaacnewton","host":"kosmos.org","nick":"isaacnewton","group":"Friends","subs":"both"}' }
     end
   end
 end