diff --git a/README.html b/README.html
index f8b9a896..15503b3d 100644
--- a/README.html
+++ b/README.html
@@ -1020,6 +1020,7 @@ and at <a href="http://luaj.sourceforge.net/api/2.0/index.html">http://luaj.sour
 <tr valign="top"><td>&nbsp;&nbsp;<b>3.0.2</b></td><td><ul>
 <li>Fix JsePlatform.luaMain() to provide an "arg" table in the chunk's environment.</li>
 <li>Let JsePlatform.luaMain() return values returned by the main chunk.</li>
+<li>Add synchronization to CoerceJavaToLua.COERCIONS map.</li>
 
 </ul></td></tr>
 </table></td></tr></table>
diff --git a/src/jse/org/luaj/vm2/lib/jse/CoerceJavaToLua.java b/src/jse/org/luaj/vm2/lib/jse/CoerceJavaToLua.java
index 36c5d824..177f9acf 100644
--- a/src/jse/org/luaj/vm2/lib/jse/CoerceJavaToLua.java
+++ b/src/jse/org/luaj/vm2/lib/jse/CoerceJavaToLua.java
@@ -21,6 +21,7 @@
 ******************************************************************************/
 package org.luaj.vm2.lib.jse;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -133,7 +134,7 @@ public class CoerceJavaToLua {
 	}
 
 
-	static final Map COERCIONS = new HashMap();
+	static final Map COERCIONS = Collections.synchronizedMap(new HashMap());
 	
 	static {
 		Coercion boolCoercion = new BoolCoercion() ;