diff --git a/libstdc++-v3/include/debug/debug.h b/libstdc++-v3/include/debug/debug.h
index 28e250f0c50..f4233760426 100644
--- a/libstdc++-v3/include/debug/debug.h
+++ b/libstdc++-v3/include/debug/debug.h
@@ -118,10 +118,17 @@ namespace __gnu_debug
   __glibcxx_check_heap(_First,_Last)
 # define __glibcxx_requires_heap_pred(_First,_Last,_Pred)	\
   __glibcxx_check_heap_pred(_First,_Last,_Pred)
-# define __glibcxx_requires_string(_String)	\
+# if __cplusplus < 201103L
+#  define __glibcxx_requires_string(_String)	\
   _GLIBCXX_DEBUG_PEDASSERT(_String != 0)
-# define __glibcxx_requires_string_len(_String,_Len)	\
+#  define __glibcxx_requires_string_len(_String,_Len)	\
   _GLIBCXX_DEBUG_PEDASSERT(_String != 0 || _Len == 0)
+# else
+#  define __glibcxx_requires_string(_String)	\
+  _GLIBCXX_DEBUG_PEDASSERT(_String != nullptr)
+#  define __glibcxx_requires_string_len(_String,_Len)	\
+  _GLIBCXX_DEBUG_PEDASSERT(_String != nullptr || _Len == 0)
+# endif
 # define __glibcxx_requires_irreflexive(_First,_Last)	\
   __glibcxx_check_irreflexive(_First,_Last)
 # define __glibcxx_requires_irreflexive2(_First,_Last)	\
diff --git a/libstdc++-v3/include/debug/string b/libstdc++-v3/include/debug/string
index c32eb41eacd..574a78e3dac 100644
--- a/libstdc++-v3/include/debug/string
+++ b/libstdc++-v3/include/debug/string
@@ -50,14 +50,25 @@
 #endif
 
 #ifdef _GLIBCXX_DEBUG_PEDANTIC
-# define __glibcxx_check_string(_String)				\
+# if __cplusplus < 201103L
+#  define __glibcxx_check_string(_String)			\
   _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(_String != 0,		\
 				    __FILE__, __LINE__,		\
 				    __PRETTY_FUNCTION__);
-# define __glibcxx_check_string_len(_String,_Len)		\
+#  define __glibcxx_check_string_len(_String,_Len)		\
   _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(_String != 0 || _Len == 0,	\
 				    __FILE__, __LINE__,		\
 				    __PRETTY_FUNCTION__);
+# else
+#  define __glibcxx_check_string(_String)			\
+  _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(_String != nullptr,		\
+				    __FILE__, __LINE__,		\
+				    __PRETTY_FUNCTION__);
+#  define __glibcxx_check_string_len(_String,_Len)		\
+  _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(_String != nullptr || _Len == 0,	\
+				    __FILE__, __LINE__,		\
+				    __PRETTY_FUNCTION__);
+# endif
 #else
 # define __glibcxx_check_string(_String)
 # define __glibcxx_check_string_len(_String,_Len)
@@ -75,8 +86,13 @@ namespace __gnu_debug
 		   const char* __function __attribute__((__unused__)))
     {
 #ifdef _GLIBCXX_DEBUG_PEDANTIC
+# if __cplusplus < 201103L
       _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(__s != 0 || __n == 0,
 					__file, __line, __function);
+# else
+      _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(__s != nullptr || __n == 0,
+					__file, __line, __function);
+# endif
 #endif
       return __s;
     }
@@ -90,8 +106,13 @@ namespace __gnu_debug
 		   const char* __function __attribute__((__unused__)))
     {
 #ifdef _GLIBCXX_DEBUG_PEDANTIC
+# if __cplusplus < 201103L
       _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(__s != 0,
 					__file, __line, __function);
+# else
+      _GLIBCXX_DEBUG_VERIFY_STR_COND_AT(__s != nullptr,
+					__file, __line, __function);
+# endif
 #endif
       return __s;
     }
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/char.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/char.cc
index cfe18e0186c..3cf85121e36 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/char.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/char.cc
@@ -20,7 +20,7 @@
 
 // basic_string ends_with
 
-#include <string>
+#include <testsuite_string.h>
 #include <testsuite_hooks.h>
 
 void
@@ -31,7 +31,7 @@ test01()
   const char cstr_suf2[] = ".rgb";
   const std::string_view sv_suf2(".rgb");
 
-  const std::string s_test("slugs/slimy.jpg");
+  const __gnu_test::string s_test("slugs/slimy.jpg");
 
   const auto cstr_in_slugs = s_test.ends_with(cstr_suf);
   VERIFY( cstr_in_slugs );
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc
index 1f2a156bace..70ab867fa4e 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc
@@ -1,10 +1,10 @@
 // { dg-options "-std=gnu++20 -Wnonnull -O0" }
 // { dg-do compile { target c++20 } }
 
-#include <string>
+#include <testsuite_string.h>
 
 void
-test01(const std::string& s)
+test01(const __gnu_test::string& s)
 {
   s.ends_with((const char*)nullptr);  // { dg-warning "\\\[-Wnonnull" }
   s.ends_with((char*)nullptr);	      // { dg-warning "\\\[-Wnonnull" }
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/wchar_t.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/wchar_t.cc
index d27e8246fb8..70b522ff69e 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/wchar_t.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/wchar_t.cc
@@ -20,7 +20,7 @@
 
 // basic_string ends_with
 
-#include <string>
+#include <testsuite_string.h>
 #include <testsuite_hooks.h>
 
 void
@@ -31,7 +31,7 @@ test01()
   const wchar_t cstr_suf2[] = L".rgb";
   const std::wstring_view sv_suf2(L".rgb");
 
-  const std::wstring s_test(L"slugs/slimy.jpg");
+  const __gnu_test::wstring s_test(L"slugs/slimy.jpg");
 
   const auto cstr_in_slugs = s_test.ends_with(cstr_suf);
   VERIFY( cstr_in_slugs );
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/char.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/char.cc
index 5c0b3afc0b6..dddf51cee16 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/char.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/char.cc
@@ -20,7 +20,7 @@
 
 // basic_string begins_with
 
-#include <string>
+#include <testsuite_string.h>
 #include <testsuite_hooks.h>
 
 void
@@ -31,7 +31,7 @@ test01()
   const char cstr_dir2[] = "worms/";
   const std::string_view sv_dir2("worms/");
 
-  const std::string s_test("slugs/slimy.jpg");
+  const __gnu_test::string s_test("slugs/slimy.jpg");
 
   const auto cstr_in_slugs = s_test.starts_with(cstr_dir);
   VERIFY( cstr_in_slugs );
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc
index 8514359c877..34614be0ab6 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc
@@ -1,10 +1,10 @@
 // { dg-options "-std=gnu++20 -Wnonnull -O0" }
 // { dg-do compile { target c++20 } }
 
-#include <string>
+#include <testsuite_string.h>
 
 void
-test01(const std::string& s)
+test01(const __gnu_test::string& s)
 {
   s.starts_with((const char*)nullptr);  // { dg-warning "\\\[-Wnonnull" }
   s.starts_with((char*)nullptr);	// { dg-warning "\\\[-Wnonnull" }
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/wchar_t.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/wchar_t.cc
index eda73212ea0..747b23ae5c2 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/wchar_t.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/wchar_t.cc
@@ -20,7 +20,7 @@
 
 // basic_string begins_with
 
-#include <string>
+#include <testsuite_string.h>
 #include <testsuite_hooks.h>
 
 void
@@ -31,7 +31,7 @@ test01()
   const wchar_t cstr_dir2[] = L"worms/";
   const std::wstring_view sv_dir2(L"worms/");
 
-  const std::wstring s_test(L"slugs/slimy.jpg");
+  const __gnu_test::wstring s_test(L"slugs/slimy.jpg");
 
   const auto cstr_in_slugs = s_test.starts_with(cstr_dir);
   VERIFY( cstr_in_slugs );