diff --git a/.cvsignore b/.cvsignore
index 070767d827..1f052ced6b 100644
--- a/.cvsignore
+++ b/.cvsignore
@@ -6,6 +6,7 @@ Makefile.in
 TAGS
 TAGS.stamp
 aclocal.m4
+autom4te-2.53.cache
 configure
 config.cache
 config.guess
diff --git a/configure.in b/configure.in
index 82ba9a09a4..244500b2e0 100644
--- a/configure.in
+++ b/configure.in
@@ -830,9 +830,9 @@ chmod u+x src/bin/overrides/gnucash-make-guids
 
 AUTOCONF_VERSION=`autoconf --version`
 autoconf_major_version=`echo ${AUTOCONF_VERSION} | \
-	sed 's/^.*Autoconf.* \([0-9]*\)\.\([0-9]*\).*$/\1/'`
+	sed 's/^.*Autoconf.* \([[0-9]]*\)\.\([[0-9]]*\).*$/\1/'`
 autoconf_minor_version=`echo ${AUTOCONF_VERSION} | \
-	sed 's/^.*Autoconf.* \([0-9]*\)\.\([0-9]*\).*$/\2/'`
+	sed 's/^.*Autoconf.* \([[0-9]]*\)\.\([[0-9]]*\).*$/\2/'`
 if test "$autoconf_major_version" -gt 2   -o \
     \( "$autoconf_major_version" -eq 2   -a \
       "$autoconf_minor_version" -gt 52 \)  ; then