diff --git a/frup.cpp b/frup.cpp
index fb06e80..7254017 100644
--- a/frup.cpp
+++ b/frup.cpp
@@ -296,7 +296,7 @@
     while (area_offset < areabuflen &&
            areabufptr[area_offset] != IPMI_FRU_SENTINEL_VALUE)
     {
-        ipmi_fru_field_t* field_ptr = NULL;
+        ipmi_fru_field_t* field_ptr = nullptr;
 
         if (chassis_custom_fields && chassis_custom_fields_len)
         {
@@ -424,7 +424,7 @@
     while (area_offset < areabuflen &&
            areabufptr[area_offset] != IPMI_FRU_SENTINEL_VALUE)
     {
-        ipmi_fru_field_t* field_ptr = NULL;
+        ipmi_fru_field_t* field_ptr = nullptr;
 
         if (board_custom_fields && board_custom_fields_len)
         {
@@ -562,7 +562,7 @@
     while (area_offset < areabuflen &&
            areabufptr[area_offset] != IPMI_FRU_SENTINEL_VALUE)
     {
-        ipmi_fru_field_t* field_ptr = NULL;
+        ipmi_fru_field_t* field_ptr = nullptr;
 
         if (product_custom_fields && product_custom_fields_len)
         {
@@ -666,7 +666,7 @@
     if (bin_in_ascii)
     {
         free(bin_in_ascii);
-        bin_in_ascii = NULL;
+        bin_in_ascii = nullptr;
     }
 }
 
@@ -734,7 +734,7 @@
             printf("Board : Buf len = [%d]\n", len);
 #endif
             ipmi_fru_board_info_area(
-                (uint8_t*)msgbuf + 2, len, NULL, &mfg_date_time,
+                (uint8_t*)msgbuf + 2, len, nullptr, &mfg_date_time,
                 &vpd_info[OPENBMC_VPD_KEY_BOARD_MFR],
                 &vpd_info[OPENBMC_VPD_KEY_BOARD_NAME],
                 &vpd_info[OPENBMC_VPD_KEY_BOARD_SERIAL_NUM],
@@ -766,7 +766,7 @@
             printf("Product : Buf len = [%d]\n", len);
 #endif
             ipmi_fru_product_info_area(
-                (uint8_t*)msgbuf + 2, len, NULL,
+                (uint8_t*)msgbuf + 2, len, nullptr,
                 &vpd_info[OPENBMC_VPD_KEY_PRODUCT_MFR],
                 &vpd_info[OPENBMC_VPD_KEY_PRODUCT_NAME],
                 &vpd_info[OPENBMC_VPD_KEY_PRODUCT_PART_MODEL_NUM],
diff --git a/strgfnhandler.cpp b/strgfnhandler.cpp
index e917783..39499db 100644
--- a/strgfnhandler.cpp
+++ b/strgfnhandler.cpp
@@ -23,12 +23,12 @@
     ipmi_response_t response, ipmi_data_len_t dataLen,
     ipmi_context_t /*context*/)
 {
-    FILE* fp = NULL;
+    FILE* fp = nullptr;
     char fruFilename[16] = {0};
     size_t offset = 0;
     size_t len = 0;
     ipmi_ret_t rc = IPMI_CC_INVALID;
-    const char* mode = NULL;
+    const char* mode = nullptr;
 
     // From the payload, extract the header that has fruid and the offsets
     auto reqptr = static_cast<write_fru_data_t*>(request);
@@ -61,7 +61,7 @@
         mode = "rb+";
     }
 
-    if ((fp = std::fopen(fruFilename, mode)) != NULL)
+    if ((fp = std::fopen(fruFilename, mode)) != nullptr)
     {
         if (std::fseek(fp, offset, SEEK_SET))
         {
@@ -116,6 +116,6 @@
     std::printf("Registering NetFn:[0x%X], Cmd:[0x%X]\n", NETFUN_STORAGE,
                 IPMI_CMD_WRITE_FRU_DATA);
 
-    ipmi_register_callback(NETFUN_STORAGE, IPMI_CMD_WRITE_FRU_DATA, NULL,
+    ipmi_register_callback(NETFUN_STORAGE, IPMI_CMD_WRITE_FRU_DATA, nullptr,
                            ipmiStorageWriteFruData, SYSTEM_INTERFACE);
 }
diff --git a/writefrudata.cpp b/writefrudata.cpp
index 44117ae..a4d5509 100644
--- a/writefrudata.cpp
+++ b/writefrudata.cpp
@@ -44,7 +44,7 @@
  */
 int cleanupError(FILE* fruFilePointer, FruAreaVector& fruAreaVec)
 {
-    if (fruFilePointer != NULL)
+    if (fruFilePointer != nullptr)
     {
         std::fclose(fruFilePointer);
     }
@@ -653,7 +653,7 @@
     }
 
     FILE* fruFilePointer = std::fopen(fruFilename, "rb");
-    if (fruFilePointer == NULL)
+    if (fruFilePointer == nullptr)
     {
         log<level::ERR>("Unable to open FRU file",
                         entry("FILE=%s", fruFilename),
@@ -687,7 +687,7 @@
 
     // We are done reading.
     std::fclose(fruFilePointer);
-    fruFilePointer = NULL;
+    fruFilePointer = nullptr;
 
     rc = ipmiValidateCommonHeader(fruData.data(), dataLen);
     if (rc < 0)