diff --git a/configure.ac b/configure.ac
index 210002b2..688e18ef 100644
--- a/configure.ac
+++ b/configure.ac
@@ -137,7 +137,6 @@ gl_INIT
 # Checks for library functions.
 AC_CHECK_FUNCS_ONCE([setlocale])
 AM_WITH_DMALLOC
-BISON_PREREQ_SUBPIPE
 BISON_PREREQ_TIMEVAR
 
 # Gettext.
diff --git a/m4/subpipe.m4 b/m4/subpipe.m4
deleted file mode 100644
index 0079c045..00000000
--- a/m4/subpipe.m4
+++ /dev/null
@@ -1,28 +0,0 @@
-# -*- Autoconf -*-
-# Checks required to run `subpipe'.
-#
-# Copyright (C) 2002-2003, 2005, 2009-2012 Free Software Foundation,
-# Inc.
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# Written by Paul Eggert <eggert@twinsun.com>.
-
-AC_DEFUN([BISON_PREREQ_SUBPIPE],
-[
- AC_TYPE_PID_T
- AC_HEADER_SYS_WAIT
- AC_CHECK_FUNCS(dup2 waitpid)
- AC_FUNC_FORK
-])