diff --git a/client_library/client_dbus.cc b/client_library/client_dbus.cc
index 48a563b..18ae23b 100644
--- a/client_library/client_dbus.cc
+++ b/client_library/client_dbus.cc
@@ -92,13 +92,8 @@
         dlc_parameters.add_dlc_module_infos();
     dlc_module_info->set_dlc_id(dlc_id);
   }
-  string dlc_request;
-  if (dlc_parameters.SerializeToString(&dlc_request)) {
-    return proxy_->AttemptInstall(dlc_request, nullptr /* brillo::ErrorPtr* */);
-  } else {
-    LOG(ERROR) << "Fail to serialize a protobuf to a string.";
-    return false;
-  }
+  return proxy_->AttemptInstall(dlc_parameters,
+                                nullptr /* brillo::ErrorPtr* */);
 }
 
 bool DBusUpdateEngineClient::GetStatus(int64_t* out_last_checked_time,
diff --git a/client_library/client_dbus.h b/client_library/client_dbus.h
index 1b127e3..c9631cf 100644
--- a/client_library/client_dbus.h
+++ b/client_library/client_dbus.h
@@ -23,6 +23,7 @@
 #include <vector>
 
 #include <base/macros.h>
+#include <dlcservice/proto_bindings/dlcservice.pb.h>
 #include <update_engine/proto_bindings/update_engine.pb.h>
 
 #include "update_engine/client_library/include/update_engine/client.h"