diff --git a/user/src/com/google/gwt/user/rebind/rpc/SerializableTypeOracleBuilder.java b/user/src/com/google/gwt/user/rebind/rpc/SerializableTypeOracleBuilder.java
index 89490c0..04a07a7 100644
--- a/user/src/com/google/gwt/user/rebind/rpc/SerializableTypeOracleBuilder.java
+++ b/user/src/com/google/gwt/user/rebind/rpc/SerializableTypeOracleBuilder.java
@@ -850,6 +850,11 @@
 
       type = type.getErasedType();
 
+      if (type.getLeafType().getQualifiedSourceName().equals("java.lang.JsException")) {
+        // JsException is not considered serializable since it is never available at JVM.
+        continue;
+      }
+
       if (tic.isInstantiable()) {
         assert (!type.isAbstract() || type.isEnum() != null);