diff --git a/phosphor-regulators/test/validate-regulators-config_tests.cpp b/phosphor-regulators/test/validate-regulators-config_tests.cpp
index 3bc52da..7e0cf20 100644
--- a/phosphor-regulators/test/validate-regulators-config_tests.cpp
+++ b/phosphor-regulators/test/validate-regulators-config_tests.cpp
@@ -162,7 +162,7 @@
     }
     while (!std::feof(pipe))
     {
-        if (fgets(buffer, sizeof buffer, pipe) != NULL)
+        if (fgets(buffer, sizeof buffer, pipe) != nullptr)
         {
             result += buffer;
         }