--- a/autogen.sh
+++ b/autogen.sh
@@ -664,6 +664,9 @@
         touch -r aclocal.m4 config/libtool.m4
     fi
 
+    # Ensure libtool.m4 is very old so that make does not rebuild aclocal.m4
+    touch -t 197001010000.00 config/libtool.m4
+
     run_and_check $ompi_autoconf
 
     run_and_check $ompi_automake --foreign -a --copy --include-deps