--- ptlib-2.18.8/src/ptlib/common/pchannel.cxx.orig	2022-12-13 13:06:48.361569790 +0100
+++ ptlib-2.18.8/src/ptlib/common/pchannel.cxx	2022-12-13 13:07:50.769126154 +0100
@@ -149,7 +149,7 @@
 {
   PChannelStreamBuffer * buf = dynamic_cast<PChannelStreamBuffer *>(rdbuf());
 #if P_HAS_SET_RDBUF
-  set_rdbuf(NULL);
+  rdbuf(NULL);
 #elif !defined(_MSC_VER)
   init(NULL);
 #endif
--- ptlib-2.18.8/src/ptlib/common/contain.cxx.orig	2022-12-13 13:09:55.608244429 +0100
+++ ptlib-2.18.8/src/ptlib/common/contain.cxx	2022-12-13 13:10:11.291208728 +0100
@@ -2612,7 +2612,7 @@
 {
   PStringStream::Buffer * buf = dynamic_cast<PStringStream::Buffer *>(rdbuf());
 #if P_HAS_SET_RDBUF
-  set_rdbuf(NULL);
+  rdbuf(NULL);
 #elif !defined(_MSC_VER)
   init(NULL);
 #endif