--- a/langtools/make/build.properties	Tue Oct 11 12:29:39 2016 +0200
+++ b/langtools/make/build.properties	Tue Oct 11 13:16:45 2016 +0200
@@ -24,11 +24,12 @@
 #
 
 #javac configuration for "normal build" (these will be passed to the bootstrap compiler):
-javac.opts = -XDignore.symbol.file=true -Xlint:all,-deprecation,-options -Werror -g:source,lines,vars
+javac.opts = -XDignore.symbol.file=true -Xlint:all,-deprecation,-options,-exports -Werror -g:source,lines,vars
 javac.source = 9
 javac.target = 9
 
 #version used to compile build tools
+javac.build.opts = -XDignore.symbol.file=true -Xlint:all,-deprecation,-options -Werror -g:source,lines,vars
 javac.build.source = 8
 javac.build.target = 8
 

--- a/langtools/make/build.xml	Tue Oct 11 12:29:39 2016 +0200
+++ b/langtools/make/build.xml	Tue Oct 11 13:16:45 2016 +0200
@@ -275,7 +275,7 @@
                classpath="${ant.core.lib}"
                bootclasspath="${langtools.jdk.home}/jre/lib/rt.jar"
                includeantruntime="false">
-            <compilerarg line="${javac.opts} -XDstringConcat=inline"/>
+            <compilerarg line="${javac.build.opts} -XDstringConcat=inline"/>
         </javac>
         <taskdef name="pparse"
                  classname="anttasks.PropertiesParserTask"
@@ -291,7 +291,7 @@
                destdir="${build.dir}/toolclasses/"
                classpath="${ant.core.lib}"
                includeantruntime="false">
-            <compilerarg line="${javac.opts} -XDstringConcat=inline"/>
+            <compilerarg line="${javac.build.opts} -XDstringConcat=inline"/>
         </javac>
         <taskdef name="pcompile"
                  classname="anttasks.CompilePropertiesTask"