diff --git a/include/tvm/runtime/object.h b/include/tvm/runtime/object.h
index 4d9bc6a2e83f..bba9e14aeeb1 100644
--- a/include/tvm/runtime/object.h
+++ b/include/tvm/runtime/object.h
@@ -318,16 +318,20 @@ struct ClosureCell;
  */
 class Object {
  public:
-  ObjectPtr<ObjectCell> ptr;
-  explicit Object(ObjectPtr<ObjectCell> ptr) : ptr(ptr) {}
-  explicit Object(ObjectCell* ptr) : ptr(ptr) {}
-  Object() : ptr() {}
-  Object(const Object& obj) : ptr(obj.ptr) {}
-  ObjectCell* operator->() { return this->ptr.operator->(); }
-
+  ObjectPtr<ObjectCell> ptr_;
+  explicit Object(ObjectPtr<ObjectCell> ptr) : ptr_(ptr) {}
+  explicit Object(ObjectCell* ptr) : ptr_(ptr) {}
+  Object() : ptr_() {}
+  Object(const Object& obj) : ptr_(obj.ptr_) {}
+  ObjectCell* operator->() { return this->ptr_.operator->(); }
+
+  /*! \brief Construct a tensor object. */
   static Object Tensor(const NDArray& data);
+  /*! \brief Construct a datatype object. */
   static Object Datatype(size_t tag, const std::vector<Object>& fields);
+  /*! \brief Construct a tuple object. */
   static Object Tuple(const std::vector<Object>& fields);
+  /*! \brief Construct a closure object. */
   static Object Closure(size_t func_index, const std::vector<Object>& free_vars);
 
   ObjectPtr<TensorCell> AsTensor() const;
@@ -335,27 +339,36 @@ class Object {
   ObjectPtr<ClosureCell> AsClosure() const;
 };
 
+/*! \brief An object containing an NDArray. */
 struct TensorCell : public ObjectCell {
+  /*! \brief The NDArray. */
   NDArray data;
   explicit TensorCell(const NDArray& data) : ObjectCell(ObjectTag::kTensor), data(data) {}
 };
 
+/*! \brief An object representing a structure or enumeration. */
 struct DatatypeCell : public ObjectCell {
+  /*! \brief The tag representing the constructor used. */
   size_t tag;
+  /*! \brief The fields of the structure. */
   std::vector<Object> fields;
 
   DatatypeCell(size_t tag, const std::vector<Object>& fields)
       : ObjectCell(ObjectTag::kDatatype), tag(tag), fields(fields) {}
 };
 
+/*! \brief An object representing a closure. */
 struct ClosureCell : public ObjectCell {
+  /*! \brief The index into the VM function table. */
   size_t func_index;
+  /*! \brief The free variables of the closure. */
   std::vector<Object> free_vars;
 
   ClosureCell(size_t func_index, const std::vector<Object>& free_vars)
       : ObjectCell(ObjectTag::kClosure), func_index(func_index), free_vars(free_vars) {}
 };
 
+/*! \brief Extract the NDArray from a tensor object. */
 NDArray ToNDArray(const Object& obj);
 
 /*!
diff --git a/include/tvm/runtime/packed_func.h b/include/tvm/runtime/packed_func.h
index 5800ba23a531..9fcefcbbe4b1 100644
--- a/include/tvm/runtime/packed_func.h
+++ b/include/tvm/runtime/packed_func.h
@@ -745,8 +745,8 @@ class TVMRetValue : public TVMPODValue_ {
   TVMRetValue& operator=(Object other) {
     this->Clear();
     type_code_ = kObject;
-    value_.v_handle = other.ptr.data_;
-    other.ptr.data_ = nullptr;
+    value_.v_handle = other.ptr_.data_;
+    other.ptr_.data_ = nullptr;
     return *this;
   }
   TVMRetValue& operator=(PackedFunc f) {
diff --git a/src/lang/reflection.cc b/src/lang/reflection.cc
index 73cf828e8e12..bc3d2895b811 100644
--- a/src/lang/reflection.cc
+++ b/src/lang/reflection.cc
@@ -87,7 +87,7 @@ class NodeIndexer : public AttrVisitor {
   }
 
   void Visit(const char* key, Object* value) final {
-    ObjectCell* ptr = value->ptr.get();
+    ObjectCell* ptr = value->ptr_.get();
     if (vm_obj_index.count(ptr)) return;
     CHECK_EQ(vm_obj_index.size(), vm_obj_list.size());
     vm_obj_index[ptr] = vm_obj_list.size();
@@ -214,7 +214,7 @@ class JSONAttrGetter : public AttrVisitor {
   }
   void Visit(const char* key, Object* value) final {
     node_->attrs[key] = std::to_string(
-        vm_obj_index_->at(value->ptr.get()));
+        vm_obj_index_->at(value->ptr_.get()));
   }
   // Get the node
   void Get(Node* node) {