--- configure.in.orig  2017-08-23 06:49:52.000000000 -0600
+++ configure.in       2021-03-29 14:40:50.317505290 -0600
@@ -29,9 +29,11 @@
 #   OCAMLWIN32    "yes"/"no" depending on Sys.os_type = "Win32"
 #   EXE           ".exe" if OCAMLWIN32=yes, "" otherwise
 
+AC_INIT([ocplib-simplex], [0.4])
+
 # check for one particular file of the sources 
 # ADAPT THE FOLLOWING LINE TO YOUR SOURCES!
-AC_INIT(src/core.ml)
+AC_CONFIG_SRCDIR([src/core.ml])
 
 # Check for Ocaml compilers
 
@@ -137,5 +139,6 @@ AC_SUBST(OCAMLWIN32)
 AC_SUBST(EXE)
 
 # Finally create the Makefile.configurable from Makefile.configurable.in
-AC_OUTPUT(Makefile)
+AC_CONFIG_FILES([Makefile])
+AC_OUTPUT
 chmod a-w Makefile