From a144eb1415a4df24dedf94cb6fc56e561af3b7ee Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Thu, 11 Dec 2014 10:44:02 +0100
Subject: [PATCH] Don't use ?=

---
 doc/manual/local.mk | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/manual/local.mk b/doc/manual/local.mk
index 0f5bfcdad..8511e8359 100644
--- a/doc/manual/local.mk
+++ b/doc/manual/local.mk
@@ -9,8 +9,8 @@ XSLTPROC = $(xsltproc) --nonet $(xmlflags) \
   --param contrib.inline.enabled 0 \
   --stringparam generate.toc "book toc"
 
-docbookxsl ?= http://docbook.sourceforge.net/release/xsl-ns/1.78.1
-docbookrng ?= http://docbook.org/xml/5.0/rng/docbook.rng
+docbookxsl = http://docbook.sourceforge.net/release/xsl-ns/1.78.1
+docbookrng = http://docbook.org/xml/5.0/rng/docbook.rng
 
 MANUAL_SRCS := $(call rwildcard, $(d), *.xml)