diff --git a/lite/core/mir/memory_optimize_pass.cc b/lite/core/mir/memory_optimize_pass.cc
index ee78fac9a88aa339514778dcc03e2c907487fb39..fe2971777c12121d15eb99c4761965a71af2bfc2 100644
--- a/lite/core/mir/memory_optimize_pass.cc
+++ b/lite/core/mir/memory_optimize_pass.cc
@@ -123,7 +123,8 @@ void MemoryOptimizePass::CollectLifeCycleByDevice(
 
   // non-tensor(like tensor_array) variables will not be reused
   for (auto& node : graph->nodes()) {
-    if (node.IsArg() && !node.arg()->type->IsTensor()) {
+    if (node.IsArg() && (node.arg()->type != nullptr) &&
+        !node.arg()->type->IsTensor()) {
       invalid_var_names.insert(node.arg()->name);
     }
   }
diff --git a/lite/core/mir/node.h b/lite/core/mir/node.h
index e7c44d2be689a9d890158c097e198314413d1ba3..45b15812fadb0789edea3f89fb00b4612bdb010f 100644
--- a/lite/core/mir/node.h
+++ b/lite/core/mir/node.h
@@ -85,7 +85,7 @@ class Node {
   struct Arg {
     std::string name;
     int id{0};
-    const Type* type{};
+    const Type* type{nullptr};
     // Weight is a special kind of argument, it is marked as weight explicitly
     // so that some weight related optimization can take place.
     bool is_weight{false};