diff --git a/libc/test/UnitTest/HermeticTestUtils.cpp b/libc/test/UnitTest/HermeticTestUtils.cpp
index 85e5cf02ff61..47f813b0b7a4 100644
--- a/libc/test/UnitTest/HermeticTestUtils.cpp
+++ b/libc/test/UnitTest/HermeticTestUtils.cpp
@@ -124,7 +124,7 @@ unsigned long __getauxval(unsigned long id) {
 
 } // extern "C"
 
-void *operator new(unsigned long size, void *ptr) { return ptr; }
+void *operator new(size_t size, void *ptr) { return ptr; }
 
 void *operator new(size_t size) { return malloc(size); }
 
@@ -137,3 +137,16 @@ void operator delete(void *) {
 }
 
 void operator delete(void *ptr, size_t size) { __builtin_trap(); }
+
+// Defining members in the std namespace is not preferred. But, we do it here
+// so that we can use it to define the operator new which takes std::align_val_t
+// argument.
+namespace std {
+enum class align_val_t : size_t {};
+} // namespace std
+
+void operator delete(void *mem, std::align_val_t) noexcept { __builtin_trap(); }
+
+void operator delete(void *mem, unsigned int, std::align_val_t) noexcept {
+  __builtin_trap();
+}