diff --git a/include/openbmc_dbus_rest.hpp b/include/openbmc_dbus_rest.hpp
index c8673d1..73986b9 100644
--- a/include/openbmc_dbus_rest.hpp
+++ b/include/openbmc_dbus_rest.hpp
@@ -1071,7 +1071,7 @@
 int readVariantFromMessage(sdbusplus::message::message &m, nlohmann::json &data)
 {
     const char *containerType;
-    int r = sd_bus_message_peek_type(m.get(), NULL, &containerType);
+    int r = sd_bus_message_peek_type(m.get(), nullptr, &containerType);
     if (r < 0)
     {
         BMCWEB_LOG_ERROR << "sd_bus_message_peek_type failed";