diff -r dd76ce4a7e22 -r 99b45154eb2c configure
--- a/configure	Thu Aug 30 13:06:54 2012 +0100
+++ b/configure	Thu Aug 30 13:08:02 2012 +0100
@@ -4613,7 +4613,8 @@
 
 
 # Check bison version, we need a version great or equal than 2.4 to build matiec.
-[[ $(bison --version) =~ ([0-9][.][0-9]*) ]] && version_bison="${BASH_REMATCH[1]}"
+version_bison="$(bison --version | sed q | cut -d' ' -f4)"
+version_bison=${version_bison:0:3}
 
 if awk -v ver="$version_bison" 'BEGIN { if (ver < 2.4) exit 1; }'; then :
   have_bison_correct=yes