diff --git a/src/shrpx_client_handler.h b/src/shrpx_client_handler.h
index 3e7243d4..7ad5c61a 100644
--- a/src/shrpx_client_handler.h
+++ b/src/shrpx_client_handler.h
@@ -135,7 +135,7 @@ public:
                        int64_t body_bytes_sent);
   WorkerStat *get_worker_stat() const;
 
-  using WriteBuf = Buffer<65536>;
+  using WriteBuf = Buffer<32768>;
   using ReadBuf = Buffer<8192>;
 
   WriteBuf *get_wb();