diff --git a/configure b/configure
index fad817bb38..3fd4cecbeb 100755
--- a/configure
+++ b/configure
@@ -11635,62 +11635,6 @@ if test "$ac_res" != no; then :
 
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing pthread_barrier_wait" >&5
-$as_echo_n "checking for library containing pthread_barrier_wait... " >&6; }
-if ${ac_cv_search_pthread_barrier_wait+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char pthread_barrier_wait ();
-int
-main ()
-{
-return pthread_barrier_wait ();
-  ;
-  return 0;
-}
-_ACEOF
-for ac_lib in '' pthread; do
-  if test -z "$ac_lib"; then
-    ac_res="none required"
-  else
-    ac_res=-l$ac_lib
-    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
-  fi
-  if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_pthread_barrier_wait=$ac_res
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext
-  if ${ac_cv_search_pthread_barrier_wait+:} false; then :
-  break
-fi
-done
-if ${ac_cv_search_pthread_barrier_wait+:} false; then :
-
-else
-  ac_cv_search_pthread_barrier_wait=no
-fi
-rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_pthread_barrier_wait" >&5
-$as_echo "$ac_cv_search_pthread_barrier_wait" >&6; }
-ac_res=$ac_cv_search_pthread_barrier_wait
-if test "$ac_res" != no; then :
-  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
-
-fi
-
 # Solaris:
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fdatasync" >&5
 $as_echo_n "checking for library containing fdatasync... " >&6; }
@@ -11978,6 +11922,65 @@ if test "$ac_res" != no; then :
 fi
 
 
+if test "$enable_thread_safety" = yes; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing pthread_barrier_wait" >&5
+$as_echo_n "checking for library containing pthread_barrier_wait... " >&6; }
+if ${ac_cv_search_pthread_barrier_wait+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_barrier_wait ();
+int
+main ()
+{
+return pthread_barrier_wait ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' pthread; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_search_pthread_barrier_wait=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if ${ac_cv_search_pthread_barrier_wait+:} false; then :
+  break
+fi
+done
+if ${ac_cv_search_pthread_barrier_wait+:} false; then :
+
+else
+  ac_cv_search_pthread_barrier_wait=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_pthread_barrier_wait" >&5
+$as_echo "$ac_cv_search_pthread_barrier_wait" >&6; }
+ac_res=$ac_cv_search_pthread_barrier_wait
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+fi
+
 if test "$with_readline" = yes; then
 
 
@@ -15939,19 +15942,6 @@ esac
 
 fi
 
-ac_fn_c_check_func "$LINENO" "pthread_barrier_wait" "ac_cv_func_pthread_barrier_wait"
-if test "x$ac_cv_func_pthread_barrier_wait" = xyes; then :
-  $as_echo "#define HAVE_PTHREAD_BARRIER_WAIT 1" >>confdefs.h
-
-else
-  case " $LIBOBJS " in
-  *" pthread_barrier_wait.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS pthread_barrier_wait.$ac_objext"
- ;;
-esac
-
-fi
-
 ac_fn_c_check_func "$LINENO" "pwrite" "ac_cv_func_pwrite"
 if test "x$ac_cv_func_pwrite" = xyes; then :
   $as_echo "#define HAVE_PWRITE 1" >>confdefs.h
@@ -16058,6 +16048,23 @@ fi
 
 
 
+if test "$enable_thread_safety" = yes; then
+  ac_fn_c_check_func "$LINENO" "pthread_barrier_wait" "ac_cv_func_pthread_barrier_wait"
+if test "x$ac_cv_func_pthread_barrier_wait" = xyes; then :
+  $as_echo "#define HAVE_PTHREAD_BARRIER_WAIT 1" >>confdefs.h
+
+else
+  case " $LIBOBJS " in
+  *" pthread_barrier_wait.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS pthread_barrier_wait.$ac_objext"
+ ;;
+esac
+
+fi
+
+
+fi
+
 if test "$PORTNAME" = "win32" -o "$PORTNAME" = "cygwin"; then
 	# Cygwin and (apparently, based on test results) Mingw both
 	# have a broken strtof(), so substitute the same replacement
diff --git a/configure.ac b/configure.ac
index 0ed53571dd..2f1585adc0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1143,7 +1143,6 @@ AC_SEARCH_LIBS(getopt_long, [getopt gnugetopt])
 AC_SEARCH_LIBS(shm_open, rt)
 AC_SEARCH_LIBS(shm_unlink, rt)
 AC_SEARCH_LIBS(clock_gettime, [rt posix4])
-AC_SEARCH_LIBS(pthread_barrier_wait, pthread)
 # Solaris:
 AC_SEARCH_LIBS(fdatasync, [rt posix4])
 # Required for thread_test.c on Solaris
@@ -1156,6 +1155,10 @@ AC_SEARCH_LIBS(shmget, cygipc)
 # *BSD:
 AC_SEARCH_LIBS(backtrace_symbols, execinfo)
 
+if test "$enable_thread_safety" = yes; then
+  AC_SEARCH_LIBS(pthread_barrier_wait, pthread)
+fi
+
 if test "$with_readline" = yes; then
   PGAC_CHECK_READLINE
   if test x"$pgac_cv_check_readline" = x"no"; then
@@ -1744,7 +1747,6 @@ AC_REPLACE_FUNCS(m4_normalize([
 	mkdtemp
 	pread
 	preadv
-	pthread_barrier_wait
 	pwrite
 	pwritev
 	random
@@ -1755,6 +1757,10 @@ AC_REPLACE_FUNCS(m4_normalize([
 	strtof
 ]))
 
+if test "$enable_thread_safety" = yes; then
+  AC_REPLACE_FUNCS(pthread_barrier_wait)
+fi
+
 if test "$PORTNAME" = "win32" -o "$PORTNAME" = "cygwin"; then
 	# Cygwin and (apparently, based on test results) Mingw both
 	# have a broken strtof(), so substitute the same replacement