diff -r 71c04702a3d5 -r 72e3ae9a25eb make/ToolsJdk.gmk
--- a/make/ToolsJdk.gmk	Tue Sep 12 19:03:39 2017 +0200
+++ b/make/ToolsJdk.gmk	Tue Sep 12 19:03:56 2017 +0200
@@ -29,7 +29,7 @@
 include JavaCompilation.gmk
 
 # Hook to include the corresponding custom file, if present.
-$(eval $(call IncludeCustomExtension, jdk, Tools.gmk))
+$(eval $(call IncludeCustomExtension, , Tools.gmk))
 
 ################################################################################
 # To avoid reevaluating the compilation setup for the tools each time this file
@@ -60,7 +60,7 @@
 TOOL_CHARACTERNAME = $(JAVA_SMALL) -cp $(BUILDTOOLS_OUTPUTDIR)/jdk_tools_classes \
     build.tools.generatecharacter.CharacterName
 
-TOOL_DTDBUILDER = $(JAVA_SMALL) -Ddtd_home=$(JDK_TOPDIR)/make/data/dtdbuilder \
+TOOL_DTDBUILDER = $(JAVA_SMALL) -Ddtd_home=$(TOPDIR)/make/data/dtdbuilder \
     -Djava.awt.headless=true \
     -cp $(BUILDTOOLS_OUTPUTDIR)/jdk_tools_classes build.tools.dtdbuilder.DTDBuilder