--- old/make/gensrc/GensrcCharacterData.gmk	2020-03-23 19:56:30.575962746 +0100
+++ new/make/gensrc/GensrcCharacterData.gmk	2020-03-23 19:56:30.279962749 +0100
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2020, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,9 @@
 # Rules to create $(SUPPORT_OUTPUTDIR)/gensrc/java.base/sun/lang/CharacterData*.java
 #
 
+TOOL_GENERATECHARACTER = $(JAVA_SMALL) -cp $(BUILDTOOLS_OUTPUTDIR)/jdk_tools_classes \
+    org.openjdk.buildtools.generatecharacter.GenerateCharacter
+
 GENSRC_CHARACTERDATA :=
 
 CHARACTERDATA = $(TOPDIR)/make/data/characterdata