diff --git a/src/Derivative.cpp b/src/Derivative.cpp
index 2520d27e290f..e64fb4ada94b 100644
--- a/src/Derivative.cpp
+++ b/src/Derivative.cpp
@@ -337,8 +337,7 @@ void ReverseAccumulationVisitor::propagate_adjoints(
             let_var_mapping.clear();
             let_variables.clear();
             for (const auto &expr : expr_list) {
-                if (expr.get()->node_type == IRNodeType::Let) {
-                    const Let *op = expr.as<Let>();
+                if (const Let *op = expr.as<Let>()) {
                     // Assume Let variables are unique
                     internal_assert(let_var_mapping.find(op->name) == let_var_mapping.end());
                     let_var_mapping[op->name] = op->value;
@@ -660,8 +659,7 @@ void ReverseAccumulationVisitor::propagate_adjoints(
             let_var_mapping.clear();
             let_variables.clear();
             for (const auto &expr : expr_list) {
-                if (expr.get()->node_type == IRNodeType::Let) {
-                    const Let *op = expr.as<Let>();
+                if (const Let *op = expr.as<Let>()) {
                     // Assume Let variables are unique
                     internal_assert(let_var_mapping.find(op->name) == let_var_mapping.end());
                     let_var_mapping[op->name] = op->value;
diff --git a/src/Serialization.cpp b/src/Serialization.cpp
index 27bea2f5cfa3..15722d878974 100644
--- a/src/Serialization.cpp
+++ b/src/Serialization.cpp
@@ -410,7 +410,7 @@ std::pair<Serialize::Stmt, Offset<void>> Serializer::serialize_stmt(FlatBufferBu
     if (!stmt.defined()) {
         return std::make_pair(Serialize::Stmt::UndefinedStmt, Serialize::CreateUndefinedStmt(builder).Union());
     }
-    switch (stmt->node_type) {
+    switch (stmt.node_type()) {
     case IRNodeType::LetStmt: {
         const auto *const let_stmt = stmt.as<LetStmt>();
         const auto name_serialized = serialize_string(builder, let_stmt->name);
@@ -681,7 +681,7 @@ std::pair<Serialize::Expr, Offset<void>> Serializer::serialize_expr(FlatBufferBu
     if (!expr.defined()) {
         return std::make_pair(Serialize::Expr::UndefinedExpr, Serialize::CreateUndefinedExpr(builder).Union());
     }
-    switch (expr->node_type) {
+    switch (expr.node_type()) {
     case IRNodeType::IntImm: {
         const auto *const int_imm = expr.as<IntImm>();
         const auto type_serialized = serialize_type(builder, int_imm->type);