diff --git a/libpldmresponder/pdr.cpp b/libpldmresponder/pdr.cpp
index 9a149f7..0d2d12a 100644
--- a/libpldmresponder/pdr.cpp
+++ b/libpldmresponder/pdr.cpp
@@ -16,8 +16,8 @@
 {
     uint8_t* pdrData = nullptr;
     uint32_t pdrSize{};
-    auto record = pldm_pdr_find_record_by_type(inRepo.getPdr(), pdrType, NULL,
-                                               &pdrData, &pdrSize);
+    auto record = pldm_pdr_find_record_by_type(inRepo.getPdr(), pdrType,
+                                               nullptr, &pdrData, &pdrSize);
     while (record)
     {
         PdrEntry pdrEntry{};
diff --git a/libpldmresponder/platform.cpp b/libpldmresponder/platform.cpp
index b8ac0f6..2329213 100644
--- a/libpldmresponder/platform.cpp
+++ b/libpldmresponder/platform.cpp
@@ -241,7 +241,7 @@
     {
         pdr_utils::PdrEntry e;
         auto record = pdr::getRecordByHandle(pdrRepo, recordHandle, e);
-        if (record == NULL)
+        if (record == nullptr)
         {
             return CmdHandler::ccOnlyResponse(
                 request, PLDM_PLATFORM_INVALID_RECORD_HANDLE);
@@ -455,7 +455,7 @@
                                    previousEventState);
 
         // If there are no HOST PDR's, there is no further action
-        if (hostPDRHandler == NULL)
+        if (hostPDRHandler == nullptr)
         {
             return PLDM_SUCCESS;
         }
@@ -866,7 +866,7 @@
     while (pdrRecord)
     {
         pdr = reinterpret_cast<pldm_state_sensor_pdr*>(pdrEntry.data);
-        assert(pdr != NULL);
+        assert(pdr != nullptr);
         if (pdr->sensor_id != sensorId)
         {
             pdr = nullptr;
@@ -938,7 +938,7 @@
     while (pdrRecord)
     {
         pdr = reinterpret_cast<pldm_state_effecter_pdr*>(pdrEntry.data);
-        assert(pdr != NULL);
+        assert(pdr != nullptr);
         if (pdr->effecter_id != effecterId)
         {
             pdr = nullptr;
diff --git a/libpldmresponder/platform_state_sensor.hpp b/libpldmresponder/platform_state_sensor.hpp
index 20973b9..003763f 100644
--- a/libpldmresponder/platform_state_sensor.hpp
+++ b/libpldmresponder/platform_state_sensor.hpp
@@ -110,7 +110,7 @@
     while (pdrRecord)
     {
         pdr = reinterpret_cast<pldm_state_sensor_pdr*>(pdrEntry.data);
-        assert(pdr != NULL);
+        assert(pdr != nullptr);
         if (pdr->sensor_id != sensorId)
         {
             pdr = nullptr;
diff --git a/libpldmresponder/test/libpldmresponder_fru_test.cpp b/libpldmresponder/test/libpldmresponder_fru_test.cpp
index f4a1202..8eba53d 100644
--- a/libpldmresponder/test/libpldmresponder_fru_test.cpp
+++ b/libpldmresponder/test/libpldmresponder_fru_test.cpp
@@ -136,21 +136,21 @@
 
     pldm_entity_node* node =
         pldm_entity_association_tree_find(entityTree.get(), &systemEntity);
-    EXPECT_TRUE(node != NULL);
+    EXPECT_TRUE(node != nullptr);
 
     node = pldm_entity_association_tree_find(entityTree.get(), &chassisEntity);
-    ASSERT_TRUE(node != NULL);
+    ASSERT_TRUE(node != nullptr);
     test_pldm_entity_node* test_node = (test_pldm_entity_node*)node;
     EXPECT_TRUE((test_node->parent).entity_type == systemEntity.entity_type);
 
     node =
         pldm_entity_association_tree_find(entityTree.get(), &motherboardEntity);
-    ASSERT_TRUE(node != NULL);
+    ASSERT_TRUE(node != nullptr);
     test_node = (test_pldm_entity_node*)node;
     EXPECT_TRUE((test_node->parent).entity_type == chassisEntity.entity_type);
 
     node = pldm_entity_association_tree_find(entityTree.get(), &panelEntity);
-    EXPECT_TRUE(node == NULL);
+    EXPECT_TRUE(node == nullptr);
 }
 
 TEST(FruImpl, entityByObjectPath)