--- a/make/autoconf/version-numbers	Thu Mar 28 08:37:05 2019 -0700
+++ b/make/autoconf/version-numbers	Thu Mar 28 10:04:27 2019 -0700
@@ -36,6 +36,7 @@
 DEFAULT_VERSION_CLASSFILE_MAJOR=57  # "`$EXPR $DEFAULT_VERSION_FEATURE + 44`"
 DEFAULT_VERSION_CLASSFILE_MINOR=0
 DEFAULT_ACCEPTABLE_BOOT_VERSIONS="12 13"
+DEFAULT_JDK_SOURCE_TARGET_VERSION=13
 
 LAUNCHER_NAME=openjdk
 PRODUCT_NAME=OpenJDK