diff --git a/src/runtime/contrib/json/json_runtime.h b/src/runtime/contrib/json/json_runtime.h
index 0c6d0f6d7136..374a440e2902 100644
--- a/src/runtime/contrib/json/json_runtime.h
+++ b/src/runtime/contrib/json/json_runtime.h
@@ -88,8 +88,11 @@ class JSONRuntimeBase : public ModuleNode {
       // The function to initialize constant tensors.
       return PackedFunc([sptr_to_self, this](TVMArgs args, TVMRetValue* rv) {
         ICHECK_EQ(args.size(), 1U);
-        this->Init(args[0]);
-        this->initialized_ = true;
+        std::lock_guard<std::mutex> guard(this->initialize_mutex_);
+        if (!this->initialized_) {
+          this->Init(args[0]);
+          this->initialized_ = true;
+        }
         *rv = 0;
       });
     } else {
@@ -270,6 +273,8 @@ class JSONRuntimeBase : public ModuleNode {
   std::vector<uint32_t> const_idx_;
   /*! \brief Indicate if the engine has been initialized. */
   bool initialized_{false};
+  /*! \brief Initializer mutex*/
+  std::mutex initialize_mutex_;
 };
 
 }  // namespace json