diff --git a/libcxx/src/iostream.cpp b/libcxx/src/iostream.cpp
index d91f9f0c04826..416725235c340 100644
--- a/libcxx/src/iostream.cpp
+++ b/libcxx/src/iostream.cpp
@@ -18,8 +18,8 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class StreamT, class BufferT>
 union stream_data {
-  stream_data() {}
-  ~stream_data() {}
+  constexpr stream_data() {}
+  constexpr ~stream_data() {}
   struct {
     // The stream has to be the first element, since that's referenced by the stream declarations in <iostream>
     StreamT stream;
@@ -38,13 +38,19 @@ union stream_data {
 #define CHAR_MANGLING_wchar_t "_W"
 #define CHAR_MANGLING(CharT) CHAR_MANGLING_##CharT
 
+#ifdef _LIBCPP_COMPILER_CLANG_BASED
+#  define STRING_DATA_CONSTINIT constinit
+#else
+#  define STRING_DATA_CONSTINIT
+#endif
+
 #ifdef _LIBCPP_ABI_MICROSOFT
 #  define STREAM(StreamT, BufferT, CharT, var)                                                                         \
-    stream_data<StreamT<CharT>, BufferT<CharT>> var __asm__(                                                           \
+    STRING_DATA_CONSTINIT stream_data<StreamT<CharT>, BufferT<CharT>> var __asm__(                                     \
         "?" #var "@" ABI_NAMESPACE_STR "@std@@3V?$" #StreamT                                                           \
         "@" CHAR_MANGLING(CharT) "U?$char_traits@" CHAR_MANGLING(CharT) "@" ABI_NAMESPACE_STR "@std@@@12@A")
 #else
-#  define STREAM(StreamT, BufferT, CharT, var) stream_data<StreamT<CharT>, BufferT<CharT>> var
+#  define STREAM(StreamT, BufferT, CharT, var) STRING_DATA_CONSTINIT stream_data<StreamT<CharT>, BufferT<CharT>> var
 #endif
 
 // These definitions and the declarations in <iostream> technically cause ODR violations, since they have different
diff --git a/libcxx/test/std/input.output/iostreams.base/ios.base/ios.types/ios_Init/ios_Init.global.pass.cpp b/libcxx/test/std/input.output/iostreams.base/ios.base/ios.types/ios_Init/ios_Init.global.pass.cpp
new file mode 100644
index 0000000000000..ac6a7213bb722
--- /dev/null
+++ b/libcxx/test/std/input.output/iostreams.base/ios.base/ios.types/ios_Init/ios_Init.global.pass.cpp
@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <iostream>
+
+// FIXME: Remove after issue https://github.com/llvm/llvm-project/issues/127348 resolved.
+extern "C" const char* __asan_default_options() { return "check_initialization_order=true:strict_init_order=true"; }
+
+// Test that ios used from globals constructors doesn't trigger Asan initialization-order-fiasco.
+
+struct Global {
+  Global() { std::cout << "Hello!"; }
+} global;
+
+int main(int, char**) { return 0; }