diff --git a/octavia/amphorae/backends/agent/api_server/server.py b/octavia/amphorae/backends/agent/api_server/server.py
index b574076416..faada5e8b9 100644
--- a/octavia/amphorae/backends/agent/api_server/server.py
+++ b/octavia/amphorae/backends/agent/api_server/server.py
@@ -37,7 +37,7 @@ def make_json_error(ex):
 
 
 for code in six.iterkeys(exceptions.default_exceptions):
-    app.error_handler_spec[None][code] = make_json_error
+    app.register_error_handler(code, make_json_error)
 
 
 @app.route('/' + api_server.VERSION +