diff --git a/configure b/configure
index 5d85213a8778bfcd5158dd519b56f906d07b9907..e81aae154d0dde0ff9eb451d993a67fbe91796bc 100755
--- a/configure
+++ b/configure
@@ -7743,6 +7743,94 @@ if test "$ac_res" != no; then
 
 fi
 
+# Required for thread_test.c on Solaris 2.5:
+case $host_os in
+     solaris*)
+	{ echo "$as_me:$LINENO: checking for library containing gethostbyname_r" >&5
+echo $ECHO_N "checking for library containing gethostbyname_r... $ECHO_C" >&6; }
+if test "${ac_cv_search_gethostbyname_r+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char gethostbyname_r ();
+int
+main ()
+{
+return gethostbyname_r ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' nsl; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext &&
+       $as_test_x conftest$ac_exeext; then
+  ac_cv_search_gethostbyname_r=$ac_res
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
+      conftest$ac_exeext
+  if test "${ac_cv_search_gethostbyname_r+set}" = set; then
+  break
+fi
+done
+if test "${ac_cv_search_gethostbyname_r+set}" = set; then
+  :
+else
+  ac_cv_search_gethostbyname_r=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_search_gethostbyname_r" >&5
+echo "${ECHO_T}$ac_cv_search_gethostbyname_r" >&6; }
+ac_res=$ac_cv_search_gethostbyname_r
+if test "$ac_res" != no; then
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+	;;
+esac
 # Cygwin:
 { echo "$as_me:$LINENO: checking for library containing shmget" >&5
 echo $ECHO_N "checking for library containing shmget... $ECHO_C" >&6; }
diff --git a/configure.in b/configure.in
index 38c26f219403f5c061ca556112d5b7e5ca368708..ff5964d77e2302fbb4e0c5ace8ad2e09ce2da6f4 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 1.585 2009/01/11 18:02:17 tgl Exp $
+dnl $PostgreSQL: pgsql/configure.in,v 1.586 2009/01/14 16:39:58 momjian Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -870,6 +870,12 @@ AC_SEARCH_LIBS(getopt_long, [getopt gnugetopt])
 AC_SEARCH_LIBS(crypt, crypt)
 # Solaris:
 AC_SEARCH_LIBS(fdatasync, [rt posix4])
+# Required for thread_test.c on Solaris 2.5:
+case $host_os in
+     solaris*)
+	AC_SEARCH_LIBS(gethostbyname_r, nsl)
+	;;
+esac
 # Cygwin:
 AC_SEARCH_LIBS(shmget, cygipc)