diff --git a/configure b/configure
index 88f763e8318cf8f61df76fea108c2331970489a3..ba5e68a140f4635c3a6d753712a290440bd36a1e 100755
--- a/configure
+++ b/configure
@@ -13243,6 +13243,11 @@ fi
 # functions are marked "not found", which is perfect.
 #
 if test "$enable_thread_safety" = yes -a "$NEED_REENTRANT_FUNCS" = yes ; then
+
+cat >>confdefs.h <<\_ACEOF
+#define NEED_REENTRANT_FUNCS 1
+_ACEOF
+
 _CFLAGS="$CFLAGS"
 _LIBS="$LIBS"
 CFLAGS="$CFLAGS $THREAD_CPPFLAGS"
diff --git a/configure.in b/configure.in
index 3f7994fbbf4b32b6da079ee219b3147b9e7c6612..141aa6360f0950b40954b8ba6aa269bf15b99673 100644
--- a/configure.in
+++ b/configure.in
@@ -1,5 +1,5 @@
 dnl Process this file with autoconf to produce a configure script.
-dnl $PostgreSQL: pgsql/configure.in,v 1.314 2004/02/10 19:55:45 tgl Exp $
+dnl $PostgreSQL: pgsql/configure.in,v 1.315 2004/02/11 17:29:01 momjian Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -1003,6 +1003,7 @@ AC_SUBST(THREAD_LIBS)
 # functions are marked "not found", which is perfect.
 #
 if test "$enable_thread_safety" = yes -a "$NEED_REENTRANT_FUNCS" = yes ; then
+AC_DEFINE(NEED_REENTRANT_FUNCS, 1, [Define if non *_r libc functions are not thread safe])
 _CFLAGS="$CFLAGS"
 _LIBS="$LIBS"
 CFLAGS="$CFLAGS $THREAD_CPPFLAGS"
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 3b3cc095410f0b9cb35933cbb77f17d32a098e78..3b7526f37968f8835801901d7622185626db4876 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -554,6 +554,9 @@
 /* Define as the maximum alignment requirement of any C data type. */
 #undef MAXIMUM_ALIGNOF
 
+/* Define if non *_r libc functions are not thread safe */
+#undef NEED_REENTRANT_FUNCS
+
 /* Define to the address where bug reports for this package should be sent. */
 #undef PACKAGE_BUGREPORT