diff --git a/xml/Makefile.am b/xml/Makefile.am
index e3a3d041c0..b58c9277bb 100644
--- a/xml/Makefile.am
+++ b/xml/Makefile.am
@@ -1,110 +1,126 @@
 #
 # Copyright (C) 2004 Andrew Beekhof
 #
 # 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 2
 # 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, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #
 MAINTAINERCLEANFILES    = Makefile.in
 
 dtddir			= $(CRM_DTD_DIRECTORY)
 dtd_SCRIPTS		= crm.dtd crm-transitional.dtd
 
 xsltdir			= $(dtddir)
 xslt_SCRIPTS		= upgrade06.xsl upgrade-*.xsl
 
 RNGdir			= $(dtddir)
 
 # See Readme.md for details on updating schema files
-RNG_max			?= $(firstword $(shell ls -1 *.rng | sed -e 's/.*-//' -e 's/.rng//' | sort -unr))
-RNG_last		?= $(shell ls -1 *.rng | sed -e 's/.*-//' -e 's/.rng//' | sort -unr | head -n 2 | tail -n 1)
-RNG_versions		= $(shell ls -1 *.rng | sed -e 's/.*-//' -e 's/.rng//' | sort -un)
+
+# Sorted list of available numeric RNG versions,
+# extracted from filenames like NAME-MAJOR[.MINOR][.MINOR-MINOR].rng
+RNG_numeric_versions    = $(shell ls -1 *.rng \
+			  | sed -n -e 's/^.*-\([0-9.]\+\).rng$$/\1/p' \
+			  | sort -u -t. -k 1,1n -k 2,2n -k 3,3n)
+
+# The highest numeric version
+RNG_max			?= $(lastword $(RNG_numeric_versions))
+
+# The previous numeric version before $(RNG_max)
+RNG_last		?= $(shell ls -1 *.rng \
+			   | sed -n -e 's/^.*-\([0-9.]\+\).rng$$/\1/p' \
+			   | sort -u -t. -k 1,1nr -k 2,2nr -k 3,3nr \
+			   | head -n 2 | tail -n 1)
+
+# A sorted list of all RNG versions (numeric and "next")
+RNG_versions		= next $(RNG_numeric_versions)
+
 RNG_generated		= pacemaker.rng $(foreach base,$(RNG_versions),pacemaker-$(base).rng) versions.rng
 
 RNG_cfg_base	 	= options nodes resources constraints fencing acls tags
 RNG_base	 	= cib $(RNG_cfg_base) status score rule nvset
 RNG_files	 	= $(foreach base,$(RNG_base),$(wildcard $(base)*.rng))
 
 RNG_SCRIPTS		= $(RNG_files) $(RNG_generated)
 
 EXTRA_DIST		= best-match.sh
 
 best_match		= $(shell $(top_srcdir)/xml/best-match.sh $(1) $(2))
 
 versions:
 	echo "Max: $(RNG_max)"
 	echo "Available: $(RNG_versions)"
 
 versions.rng: Makefile.am
 	echo "  RNG      $@"
 	echo "<?xml version='1.0' encoding='UTF-8'?>" > $@
 	echo "<grammar xmlns='http://relaxng.org/ns/structure/1.0' datatypeLibrary='http://www.w3.org/2001/XMLSchema-datatypes'>" >> $@
 	echo "  <start>" >> $@
 	echo "   <interleave>" >> $@
 	echo "    <optional>" >> $@
 	echo "      <attribute name='validate-with'>" >> $@
 	echo "        <choice>" >> $@
 	echo "          <value>none</value>" >> $@
 	echo "          <value>pacemaker-0.6</value>" >> $@
 	echo "          <value>transitional-0.6</value>" >> $@
 	echo "          <value>pacemaker-0.7</value>" >> $@
 	echo "          <value>pacemaker-1.1</value>" >> $@
 	for rng in $(RNG_versions); do echo "          <value>pacemaker-$$rng</value>" >> $@; done
 	echo "        </choice>" >> $@
 	echo "      </attribute>" >> $@
 	echo "    </optional>" >> $@
 	echo "    <attribute name='admin_epoch'><data type='nonNegativeInteger'/></attribute>" >> $@
 	echo "    <attribute name='epoch'><data type='nonNegativeInteger'/></attribute>" >> $@
 	echo "    <attribute name='num_updates'><data type='nonNegativeInteger'/></attribute>" >> $@
 	echo "   </interleave>" >> $@
 	echo "  </start>" >> $@
 	echo "</grammar>" >> $@
 
 pacemaker.rng: pacemaker-$(RNG_max).rng
 	echo "  RNG      $@"
 	cp $(top_builddir)/xml/$< $@
 
 pacemaker-%.rng: $(RNG_files) best-match.sh Makefile.am 
 	echo "  RNG      $@"
 	echo "<?xml version='1.0' encoding='UTF-8'?>" > $@
 	echo "<grammar xmlns='http://relaxng.org/ns/structure/1.0' datatypeLibrary='http://www.w3.org/2001/XMLSchema-datatypes'>" >> $@
 	echo "  <start>" >> $@
 	echo "    <element name='cib'>" >> $@
 	$(top_srcdir)/xml/best-match.sh cib $(*) $(@) "      "
 	echo "      <element name='configuration'>" >> $@
 	echo "        <interleave>" >> $@
 	for rng in $(RNG_cfg_base); do $(top_srcdir)/xml/best-match.sh $$rng $(*) $(@) "          "; done
 	echo "        </interleave>" >> $@
 	echo "      </element>" >> $@
 	echo "      <element name='status'>" >> $@
 	$(top_srcdir)/xml/best-match.sh status $(*) $(@) "        "
 	echo "      </element>" >> $@
 	echo "    </element>" >> $@
 	echo "  </start>" >> $@
 	echo "</grammar>" >> $@
 
 files_next = $(shell echo $(wildcard *-next.rng) | sed 's/-next.rng//g')
 files_max = $(shell echo $(wildcard *-$(RNG_max).rng) | sed 's/-[0-9][0-9.]*.rng//g')
 
 diff:
 	echo "#  Comparing changes in: $(RNG_max)"
 	-for rng in $(files_max); do echo "### $${rng}"; diff -u `$(top_srcdir)/xml/best-match.sh $${rng} $(RNG_last)` $${rng}-$(RNG_max).rng; done
 	echo -e "\n\n\n#  Comparing changes since: $(RNG_max)"
 	-for rng in $(files_next); do echo "### $${rng}"; diff -u `$(top_srcdir)/xml/best-match.sh $${rng} $(RNG_max)` $${rng}-next.rng; done
 
 sync:
 	git rm -f $(wildcard *-next.rng)
 	make pacemaker-next.rng
 
 clean:
 	rm -f $(RNG_generated)