diff --git a/utilities/transactions/lock/range/range_tree/lib/locktree/wfg.cc b/utilities/transactions/lock/range/range_tree/lib/locktree/wfg.cc
index df0073e0d2..7f0ed3abb8 100644
--- a/utilities/transactions/lock/range/range_tree/lib/locktree/wfg.cc
+++ b/utilities/transactions/lock/range/range_tree/lib/locktree/wfg.cc
@@ -91,7 +91,7 @@ void wfg::add_edge(TXNID a_txnid, TXNID b_txnid) {
 // Return false otherwise.
 bool wfg::node_exists(TXNID txnid) {
   node *n = find_node(txnid);
-  return n != NULL;
+  return n != nullptr;
 }
 
 bool wfg::cycle_exists_from_node(node *target, node *head,
diff --git a/utilities/transactions/lock/range/range_tree/lib/util/dbt.cc b/utilities/transactions/lock/range/range_tree/lib/util/dbt.cc
index 4675697fd4..448e9bf51d 100644
--- a/utilities/transactions/lock/range/range_tree/lib/util/dbt.cc
+++ b/utilities/transactions/lock/range/range_tree/lib/util/dbt.cc
@@ -65,7 +65,7 @@ DBT *toku_init_dbt(DBT *dbt) {
 }
 
 DBT toku_empty_dbt(void) {
-  static const DBT empty_dbt = {.data = 0, .size = 0, .ulen = 0, .flags = 0};
+  static const DBT empty_dbt = {.data = nullptr, .size = 0, .ulen = 0, .flags = 0};
   return empty_dbt;
 }
 
@@ -118,13 +118,13 @@ void toku_sdbt_cleanup(struct simple_dbt *sdbt) {
 
 const DBT *toku_dbt_positive_infinity(void) {
   static DBT positive_infinity_dbt = {
-      .data = 0, .size = 0, .ulen = 0, .flags = 0};  // port
+      .data = nullptr, .size = 0, .ulen = 0, .flags = 0};  // port
   return &positive_infinity_dbt;
 }
 
 const DBT *toku_dbt_negative_infinity(void) {
   static DBT negative_infinity_dbt = {
-      .data = 0, .size = 0, .ulen = 0, .flags = 0};  // port
+      .data = nullptr, .size = 0, .ulen = 0, .flags = 0};  // port
   return &negative_infinity_dbt;
 }