configure.in requires at least autoconf 2.50

diff --git a/configure.in b/configure.in
index a42eb259821496ed6167634fd54e6889401e8d95..cb968294a27be7e771f678db8ff00b786b6db3e6 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -21,6 +21,7 @@ dnl IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 dnl WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 dnl PURPOSE.
 
+AC_PREREQ(2.50)
 AC_INIT(flex,2.5.7,help-flex@gnu.org)
 AC_CONFIG_SRCDIR(scan.l)
 AM_INIT_AUTOMAKE(flex,2.5.7)