diff --git a/README.md b/README.md
index 288bf76..6c29983 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,13 @@ Thanks the great projects:
 
 > Package `com.hankcs.lucene` copy from [hanlp-lucene-plugin](https://github.com/hankcs/hanlp-lucene-plugin)
 
+
+# Issue
+
+Can't use custom dictionary in JDK9. So change `targetCompatibility` to 1.8.
+
+All published releases had build on JDK9.
+
 # Build and Install
 
 ## Install lib
diff --git a/build.gradle b/build.gradle
index 7fd892c..990e8ce 100644
--- a/build.gradle
+++ b/build.gradle
@@ -29,8 +29,8 @@ apply plugin: 'java'
 apply plugin: 'idea'
 apply plugin: 'elasticsearch.esplugin'
 
-sourceCompatibility = JavaVersion.VERSION_1_9
-targetCompatibility = JavaVersion.VERSION_1_9
+sourceCompatibility = JavaVersion.VERSION_1_8
+targetCompatibility = JavaVersion.VERSION_1_8
 
 licenseFile = rootProject.file('LICENSE.txt')
 noticeFile = rootProject.file('NOTICE.txt')
diff --git a/src/main/plugin-metadata/plugin-security.policy b/src/main/plugin-metadata/plugin-security.policy
index 639f6bf..0fe34d7 100644
--- a/src/main/plugin-metadata/plugin-security.policy
+++ b/src/main/plugin-metadata/plugin-security.policy
@@ -1,31 +1,29 @@
 grant {
-  // HanLP data directories
   permission java.io.FilePermission "<<ALL FILES>>", "read,write";
-
-  // needed because of problems in unbound LDAP library
   permission java.util.PropertyPermission "*", "read,write";
-
-  // needed to set expert SSL options, etc
   permission java.lang.RuntimePermission "setFactory";
-  permission javax.net.ssl.SSLPermission "setHostnameVerifier";
-
-  // needed when sending emails for javax.activation
-  // otherwise a classnotfound exception is thrown due to trying
-  // to load the class with the application class loader
   permission java.lang.RuntimePermission "setContextClassLoader";
   permission java.lang.RuntimePermission "getClassLoader";
-  // TODO: remove use of this jar as soon as possible!!!!
   permission java.lang.RuntimePermission "accessClassInPackage.com.sun.activation.registries";
-
-  // bouncy castle
+  permission java.lang.RuntimePermission "accessClassInPackage.sun.misc";
+  permission java.lang.RuntimePermission "accessClassInPackage.sun.reflect";
+  permission java.lang.RuntimePermission "reflectionFactoryAccess";
+  permission java.lang.RuntimePermission "accessDeclaredMembers";
+  permission java.lang.RuntimePermission "accessClassInPackage.sun.jdbc.odbc";
   permission java.security.SecurityPermission "putProviderProperty.BC";
-
-  // needed for x-pack security extension
   permission java.security.SecurityPermission "createPolicy.JavaPolicy";
   permission java.security.SecurityPermission "getPolicy";
   permission java.security.SecurityPermission "setPolicy";
-
-  // Netty SelectorUtil wants to change this, because of https://bugs.openjdk.java.net/browse/JDK-6427854
-  // the bug says it only happened rarely, and that its fixed, but apparently it still happens rarely!
   permission java.util.PropertyPermission "sun.nio.ch.bugLevel", "write";
+  permission java.util.PropertyPermission "*","read,write";
+  permission java.util.PropertyPermission "file.encoding", "read";
+  permission java.util.PropertyPermission "user.dir ",   "read ";
+  permission java.util.PropertyPermission "user.home ",   "read ";
+  permission java.util.PropertyPermission "java.home ",   "read ";
+  permission java.util.PropertyPermission  "java.class.path ",   "read ";
+  permission java.lang.reflect.ReflectPermission "suppressAccessChecks";
+  permission javax.net.ssl.SSLPermission "setHostnameVerifier";
+  permission org.elasticsearch.script.ClassPermission "com.hankcs.*";
+  permission org.elasticsearch.script.ClassPermission "org.elasticsearch.*";
+  ///   permission java.lang.RuntimePermission "accessClassInPackage.jdk.internal.ref";
 };