diff --git a/test/debug_inif_test.cpp b/test/debug_inif_test.cpp
index 08cb2a7..59472ef 100644
--- a/test/debug_inif_test.cpp
+++ b/test/debug_inif_test.cpp
@@ -23,7 +23,7 @@
         std::span<char> tmpdirSpan(reinterpret_cast<char*>(tmpdir),
                                    sizeof(tmpdir));
         auto dirPtr = mkdtemp(tmpdirSpan.data());
-        if (dirPtr == NULL)
+        if (dirPtr == nullptr)
         {
             throw std::bad_alloc();
         }