diff --git a/protos/protos.h b/protos/protos.h
index a5fc14576c..9bbf650d8a 100644
--- a/protos/protos.h
+++ b/protos/protos.h
@@ -10,7 +10,6 @@
 namespace protos {
 namespace internal {
 using hpb::internal::GetInternalMsg;
-using hpb::internal::Serialize;
 }  // namespace internal
 
 using hpb::Arena;