diff --git a/buffet/manager.cc b/buffet/manager.cc
index 9a11040..ee7379f 100644
--- a/buffet/manager.cc
+++ b/buffet/manager.cc
@@ -97,8 +97,7 @@
 
 std::string Manager::HandleStartRegisterDevice(
     chromeos::ErrorPtr* error,
-    const std::map<std::string,
-    std::unique_ptr<base::Value>>& params) {
+    const std::map<std::string, std::string>& params) {
   LOG(INFO) << "Received call to Manager.StartRegisterDevice()";
 
   return device_info_->StartRegistration(params, error);