diff --git a/libretroshare/src/pqi/pqissl.h b/libretroshare/src/pqi/pqissl.h
index 915e71173..1a773b3a2 100644
--- a/libretroshare/src/pqi/pqissl.h
+++ b/libretroshare/src/pqi/pqissl.h
@@ -55,7 +55,7 @@ const int PQISSL_DNS_FLAG = 0x04;
 const int PQISSL_UDP_FLAG = 0x02;
 
 /* TCP buffer size for Windows systems */
-const int WINDOWS_TCP_BUFFER_SIZE = 128 * 1024; // 128 KB
+const int WINDOWS_TCP_BUFFER_SIZE = 512 * 1024; // 512 KB
 
 /***************************** pqi Net SSL Interface *********************************
  * This provides the base SSL interface class,