diff --git a/clang/test/CXX/drs/dr0xx.cpp b/clang/test/CXX/drs/dr0xx.cpp
--- a/clang/test/CXX/drs/dr0xx.cpp
+++ b/clang/test/CXX/drs/dr0xx.cpp
@@ -4,6 +4,7 @@
 // RUN: %clang_cc1 -std=c++17 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors -triple %itanium_abi_triple
 // RUN: %clang_cc1 -std=c++20 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors -triple %itanium_abi_triple
 // RUN: %clang_cc1 -std=c++23 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors -triple %itanium_abi_triple
+// RUN: %clang_cc1 -std=c++2b %s -verify -fexceptions -fcxx-exceptions -pedantic-errors -triple %itanium_abi_triple
 
 namespace dr1 { // dr1: no
   namespace X { extern "C" void dr1_f(int a = 1); }
@@ -1018,7 +1019,7 @@
   };
 }
 
-namespace dr78 { // dr78: sup ????
+namespace dr78 { // dr78: no
   // Under DR78, this is valid, because 'k' has static storage duration, so is
   // zero-initialized.
   const int k; // expected-error {{default initialization of an object of const}}
diff --git a/clang/test/CXX/drs/dr2xx.cpp b/clang/test/CXX/drs/dr2xx.cpp
--- a/clang/test/CXX/drs/dr2xx.cpp
+++ b/clang/test/CXX/drs/dr2xx.cpp
@@ -4,6 +4,7 @@
 // RUN: %clang_cc1 -std=c++17 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++20 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++23 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++2b %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
 
 // PR13819 -- __SIZE_TYPE__ is incompatible.
 typedef __SIZE_TYPE__ size_t; // expected-error 0-1 {{extension}}
@@ -682,6 +683,17 @@
   G::~G() {}
 }
 
+namespace dr253 { // dr253: 3.9
+struct Z {
+  operator int() const { return 0; }
+};
+
+void f() {
+  const Z z1;      
+  const Z z2 = { };
+}
+} // namespace dr253
+
 namespace dr254 { // dr254: yes
   template<typename T> struct A {
     typedef typename T::type type; // ok even if this is a typedef-name, because