--- a/make/autoconf/jdk-version.m4	Wed Dec 20 17:36:50 2017 +0100
+++ b/make/autoconf/jdk-version.m4	Wed Dec 20 09:14:06 2017 -0800
@@ -331,6 +331,10 @@
     VENDOR_VERSION_STRING="$with_vendor_version_string"
   fi
 
+  # We could define --with flags for these, if really needed
+  VERSION_CLASSFILE_MAJOR="$DEFAULT_VERSION_CLASSFILE_MAJOR"
+  VERSION_CLASSFILE_MINOR="$DEFAULT_VERSION_CLASSFILE_MINOR"
+
   AC_MSG_CHECKING([for version string])
   AC_MSG_RESULT([$VERSION_STRING])
 
@@ -348,4 +352,7 @@
   AC_SUBST(VERSION_IS_GA)
   AC_SUBST(VERSION_DATE)
   AC_SUBST(VENDOR_VERSION_STRING)
+  AC_SUBST(VERSION_CLASSFILE_MAJOR)
+  AC_SUBST(VERSION_CLASSFILE_MINOR)
+
 ])