diff --git a/orca/src/main/scala/com/intel/analytics/bigdl/orca/tfpark/TFModelBroadcast.scala b/orca/src/main/scala/com/intel/analytics/bigdl/orca/tfpark/TFModelBroadcast.scala
index 2865890d6ff..4e78edaa953 100644
--- a/orca/src/main/scala/com/intel/analytics/bigdl/orca/tfpark/TFModelBroadcast.scala
+++ b/orca/src/main/scala/com/intel/analytics/bigdl/orca/tfpark/TFModelBroadcast.scala
@@ -16,7 +16,7 @@
 
 package com.intel.analytics.zoo.tfpark
 
-import java.io.{IOException, ObjectInputStream, ObjectOutputStream}
+import java.io.{IOException, ObjectInputStream, ObjectOutputStream, InvalidClassException, InputStream, ObjectStreamClass}
 
 import com.intel.analytics.bigdl.Module
 import com.intel.analytics.bigdl.models.utils.{CachedModels, ModelBroadcast, ModelInfo}
@@ -117,7 +117,7 @@ class TFModelBroadcast[T: ClassTag]()
     } else {
       SerializationUtils.clone(broadcastParameters.value)
     }
-    //
+
     // share weight
     putWeightBias(parameters, localModel)
 
@@ -125,7 +125,6 @@ class TFModelBroadcast[T: ClassTag]()
     //    if (localModel.isInstanceOf[Container[_, _, T]] && broadcastConsts.value.nonEmpty) {
     //      putConsts(localModel.asInstanceOf[Container[_, _, T]], broadcastConsts.value)
     //    }
-    // init gradient
     if (initGradient) {
       initGradWeightBias(broadcastParameters.value, localModel)
     }
@@ -161,17 +160,28 @@ private[zoo] class ModelInfo[T: ClassTag](val uuid: String, @transient var model
   @throws(classOf[IOException])
   private def readObject(in: ObjectInputStream): Unit = {
     in.defaultReadObject()
-    model = in.readObject().asInstanceOf[Module[T]]
+    val vin = new ModelInfoObjectInputStream(in)
+    model = vin.readObject().asInstanceOf[Module[T]]
     CachedModels.add(uuid, model)
   }
 }
 
-
 private[zoo] object ModelInfo {
   def apply[T: ClassTag](uuid: String, model: Module[T])(
     implicit ev: TensorNumeric[T]): ModelInfo[T] = new ModelInfo[T](uuid, model)
 }
 
+private class ModelInfoObjectInputStream[T: ClassTag](val inputStream: InputStream)
+  extends ObjectInputStream(inputStream) {
+  @throws[IOException]
+  @throws[ClassNotFoundException]
+  override protected def resolveClass(desc: ObjectStreamClass): Class[_] = {
+    if (!desc.getName.equals(classOf[ModelInfo[T]].getName)) {
+      throw new InvalidClassException("Unrecognized Class", desc.getName)
+    }
+    super.resolveClass(desc)
+  }
+}
 
 private[zoo] object CachedModels {
 
@@ -183,7 +193,7 @@ private[zoo] object CachedModels {
 
   type Modles = ArrayBuffer[Module[_]]
 
-  private val cachedModels: concurrent.Map[String, Modles] =
+  private val cachedModels =
     new ConcurrentHashMap[String, Modles]().asScala
 
   def add[T: ClassTag](uuid: String, model: Module[T])(implicit ev: TensorNumeric[T]): Unit =