diff --git a/js/rhino/org/mozilla/javascript/ImporterTopLevel.java b/js/rhino/org/mozilla/javascript/ImporterTopLevel.java
index 45c297ef0516..6994c2c709d0 100644
--- a/js/rhino/org/mozilla/javascript/ImporterTopLevel.java
+++ b/js/rhino/org/mozilla/javascript/ImporterTopLevel.java
@@ -16,6 +16,8 @@
  * Reserved.
  */
 
+// API class
+
 package org.mozilla.javascript;
 
 import java.util.Vector;
diff --git a/js/rhino/org/mozilla/javascript/NativeJavaPackage.java b/js/rhino/org/mozilla/javascript/NativeJavaPackage.java
index 240224441879..bf71836817b0 100644
--- a/js/rhino/org/mozilla/javascript/NativeJavaPackage.java
+++ b/js/rhino/org/mozilla/javascript/NativeJavaPackage.java
@@ -135,8 +135,12 @@ public class NativeJavaPackage extends ScriptableObject {
         String newPackage = packageName.length() == 0
                             ? id 
                             : packageName + "." + id;
+        Context cx = Context.getContext();
+        SecuritySupport ss = cx.getSecuritySupport();
         Scriptable newValue;
         try {
+            if (ss != null && !ss.visibleToScripts(newPackage))
+                throw new ClassNotFoundException();
             Class newClass = Class.forName(newPackage);
             newValue =  NativeJavaClass.wrap(getTopLevelScope(this), newClass);
             newValue.setParentScope(this);
diff --git a/js/rhino/org/mozilla/javascript/SecuritySupport.java b/js/rhino/org/mozilla/javascript/SecuritySupport.java
index 8c643287bfdf..98be62f3e8d6 100644
--- a/js/rhino/org/mozilla/javascript/SecuritySupport.java
+++ b/js/rhino/org/mozilla/javascript/SecuritySupport.java
@@ -90,4 +90,17 @@ public interface SecuritySupport {
      * @return a security context object previously passed to defineClass
      */
     public Object getSecurityDomain(Class cl);
+    
+    /**
+     * Return true iff the Java class with the given name should be exposed
+     * to scripts.
+     * <p>
+     * An embedding may filter which Java classes are exposed through 
+     * LiveConnect to JavaScript scripts.
+     * @param fullClassName the full name of the class (including the package
+     *                      name, with '.' as a delimiter). For example the 
+     *                      standard string class is "java.lang.String"
+     * @return whether or not to reveal this class to scripts
+     */
+    public boolean visibleToScripts(String fullClassName);
 }
diff --git a/js/rhino/src/org/mozilla/javascript/ImporterTopLevel.java b/js/rhino/src/org/mozilla/javascript/ImporterTopLevel.java
index 45c297ef0516..6994c2c709d0 100644
--- a/js/rhino/src/org/mozilla/javascript/ImporterTopLevel.java
+++ b/js/rhino/src/org/mozilla/javascript/ImporterTopLevel.java
@@ -16,6 +16,8 @@
  * Reserved.
  */
 
+// API class
+
 package org.mozilla.javascript;
 
 import java.util.Vector;
diff --git a/js/rhino/src/org/mozilla/javascript/NativeJavaPackage.java b/js/rhino/src/org/mozilla/javascript/NativeJavaPackage.java
index 240224441879..bf71836817b0 100644
--- a/js/rhino/src/org/mozilla/javascript/NativeJavaPackage.java
+++ b/js/rhino/src/org/mozilla/javascript/NativeJavaPackage.java
@@ -135,8 +135,12 @@ public class NativeJavaPackage extends ScriptableObject {
         String newPackage = packageName.length() == 0
                             ? id 
                             : packageName + "." + id;
+        Context cx = Context.getContext();
+        SecuritySupport ss = cx.getSecuritySupport();
         Scriptable newValue;
         try {
+            if (ss != null && !ss.visibleToScripts(newPackage))
+                throw new ClassNotFoundException();
             Class newClass = Class.forName(newPackage);
             newValue =  NativeJavaClass.wrap(getTopLevelScope(this), newClass);
             newValue.setParentScope(this);
diff --git a/js/rhino/src/org/mozilla/javascript/SecuritySupport.java b/js/rhino/src/org/mozilla/javascript/SecuritySupport.java
index 8c643287bfdf..98be62f3e8d6 100644
--- a/js/rhino/src/org/mozilla/javascript/SecuritySupport.java
+++ b/js/rhino/src/org/mozilla/javascript/SecuritySupport.java
@@ -90,4 +90,17 @@ public interface SecuritySupport {
      * @return a security context object previously passed to defineClass
      */
     public Object getSecurityDomain(Class cl);
+    
+    /**
+     * Return true iff the Java class with the given name should be exposed
+     * to scripts.
+     * <p>
+     * An embedding may filter which Java classes are exposed through 
+     * LiveConnect to JavaScript scripts.
+     * @param fullClassName the full name of the class (including the package
+     *                      name, with '.' as a delimiter). For example the 
+     *                      standard string class is "java.lang.String"
+     * @return whether or not to reveal this class to scripts
+     */
+    public boolean visibleToScripts(String fullClassName);
 }