diff --git a/mace/core/mace.cc b/mace/core/mace.cc
index 5248318164b6ec34dff05a12c3ec54bd87c4c916..557ef20fe16abbdb13b0ffbecc6ca2cdca9a52e0 100644
--- a/mace/core/mace.cc
+++ b/mace/core/mace.cc
@@ -153,7 +153,9 @@ void OperatorDef::CopyFrom(const OperatorDef &from) {
   output_type_.resize(from_data_type.size());
   std::copy(from_data_type.begin(), from_data_type.end(), output_type_.begin());
 
-  mem_id_ = from.mem_id();
+  auto mem_ids = from.mem_id();
+  mem_id_.resize(mem_ids.size());
+  std::copy(mem_ids.begin(), mem_ids.end(), mem_id_.begin());
 
   // nnlib
   node_id_ = from.node_id();
@@ -186,13 +188,11 @@ void OperatorDef::set_type(const std::string &type_) {
 }
 bool OperatorDef::has_type() const { return (has_bits_ & 0x00000002u) != 0; }
 void OperatorDef::set_has_type() { has_bits_ |= 0x00000002u; }
-int OperatorDef::mem_id() const { return mem_id_; }
-void OperatorDef::set_mem_id(const int mem_id) {
-  set_has_mem_id();
-  mem_id_ = mem_id;
+const std::vector<int> &OperatorDef::mem_id() const { return mem_id_; }
+void OperatorDef::set_mem_id(const std::vector<int> &value) {
+  mem_id_.resize(value.size());
+  std::copy(value.begin(), value.end(), mem_id_.begin());
 }
-bool OperatorDef::has_mem_id() const { return (has_bits_ & 0x00000004u) != 0; }
-void OperatorDef::set_has_mem_id() { has_bits_ |= 0x00000004u; }
 uint32_t OperatorDef::node_id() const { return node_id_; }
 void OperatorDef::set_node_id(uint32_t node_id) { node_id_ = node_id; }
 uint32_t OperatorDef::op_id() const { return op_id_; }
diff --git a/mace/core/workspace.cc b/mace/core/workspace.cc
index 1cfa1802f07ab1bf6e44d8e86518ef7667575263..1e927c3eff627a9cb4b6e9cb70d76133bbab03c8 100644
--- a/mace/core/workspace.cc
+++ b/mace/core/workspace.cc
@@ -116,7 +116,7 @@ void Workspace::CreateImageOutputTensor(const NetDef &net_def) {
   // As DSP may have different data output type for each op,
   // we stick to the same concept.
   for (auto &op : net_def.op()) {
-    if (op.has_mem_id()) {
+    if (! op.mem_id().empty()){
       const DataType op_dtype = static_cast<DataType>(
           ArgumentHelper::GetSingleArgument<OperatorDef, int>(
               op, "T", static_cast<int>(DT_FLOAT)));
@@ -135,18 +135,19 @@ void Workspace::CreateImageOutputTensor(const NetDef &net_def) {
   }
   VLOG(3) << "Preallocate image to tensors";
   for (auto &op : net_def.op()) {
-    if (op.has_mem_id()) {
-      std::unique_ptr<Tensor> tensor(
-          new Tensor(preallocated_allocator_.GetBuffer(op.mem_id()), dtype));
-      tensor->SetSourceOpName(op.name());
-      VLOG(3)
-          << "Tensor: " << op.name() << "(" << op.type() << ")"
-          << "; Mem: " << op.mem_id() << "; Image shape: "
-          << dynamic_cast<Image *>(tensor->UnderlyingBuffer())->image_shape()[0]
-          << ", "
-          << dynamic_cast<Image *>(tensor->UnderlyingBuffer())
-                 ->image_shape()[1];
-      tensor_map_[op.output(0)] = std::move(tensor);
+    if (!op.mem_id().empty()) {
+      auto mem_ids = op.mem_id();
+      for (auto mem_id : mem_ids) {
+        std::unique_ptr<Tensor> tensor
+            (new Tensor(preallocated_allocator_.GetBuffer(mem_id), dtype));
+        tensor->SetSourceOpName(op.name());
+        VLOG(3) << "Tensor: " << op.name() << "(" << op.type() << ")" << "; Mem: "
+                << mem_id << "; Image shape: "
+                << dynamic_cast<Image *>(tensor->UnderlyingBuffer())->image_shape()[0]
+                << ", "
+                << dynamic_cast<Image *>(tensor->UnderlyingBuffer())->image_shape()[1];
+        tensor_map_[op.output(0)] = std::move(tensor);
+      }
     }
   }
 }
diff --git a/mace/public/mace.h b/mace/public/mace.h
index 5d4ad299e7e842d07a801c6d074b948150e6f484..3c8fc778a709d228d369e3321ca730dc8f086f94 100644
--- a/mace/public/mace.h
+++ b/mace/public/mace.h
@@ -174,9 +174,8 @@ class OperatorDef {
   const std::string &type() const;
   void set_type(const std::string &type_);
   bool has_type() const;
-  int mem_id() const;
-  void set_mem_id(const int mem_id);
-  bool has_mem_id() const;
+  const std::vector<int> &mem_id() const;
+  void set_mem_id(const std::vector<int> &value);
   uint32_t node_id() const;
   void set_node_id(uint32_t node_id);
   uint32_t op_id() const;
@@ -220,7 +219,7 @@ class OperatorDef {
   std::vector<OutputShape> output_shape_;
   std::vector<DataType> output_type_;
 
-  int mem_id_;
+  std::vector<int> mem_id_;
 
   // nnlib
   uint32_t node_id_;