diff --git a/libcxx/include/sstream b/libcxx/include/sstream
--- a/libcxx/include/sstream
+++ b/libcxx/include/sstream
@@ -420,10 +420,9 @@
         this->__pbump(__nout);
     }
     __hm_ = __hm == -1 ? nullptr : __p + __hm;
-    __p = const_cast<char_type*>(__rhs.__str_.data());
-    __rhs.setg(__p, __p, __p);
-    __rhs.setp(__p, __p);
-    __rhs.__hm_ = __p;
+    __rhs.setg(nullptr, nullptr, nullptr);
+    __rhs.setp(nullptr, nullptr);
+    __rhs.__hm_ = nullptr;
     this->pubimbue(__rhs.getloc());
 }
 
@@ -467,10 +466,9 @@
 
     __hm_ = __hm == -1 ? nullptr : __p + __hm;
     __mode_ = __rhs.__mode_;
-    __p = const_cast<char_type*>(__rhs.__str_.data());
-    __rhs.setg(__p, __p, __p);
-    __rhs.setp(__p, __p);
-    __rhs.__hm_ = __p;
+    __rhs.setg(nullptr, nullptr, nullptr);
+    __rhs.setp(nullptr, nullptr);
+    __rhs.__hm_ = nullptr;
     this->pubimbue(__rhs.getloc());
     return *this;
 }
diff --git a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.assign/move.pass.cpp b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.assign/move.pass.cpp
--- a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.assign/move.pass.cpp
+++ b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.assign/move.pass.cpp
@@ -16,48 +16,53 @@
 #include <sstream>
 #include <cassert>
 
+#include "make_string.h"
 #include "test_macros.h"
 
-int main(int, char**)
-{
-    {
-        std::stringbuf buf1("testing");
-        std::stringbuf buf;
-        buf = std::move(buf1);
-        assert(buf.str() == "testing");
-    }
-    {
-        std::stringbuf buf1("testing", std::ios_base::in);
-        std::stringbuf buf;
-        buf = std::move(buf1);
-        assert(buf.str() == "testing");
-    }
-    {
-        std::stringbuf buf1("testing", std::ios_base::out);
-        std::stringbuf buf;
-        buf = std::move(buf1);
-        assert(buf.str() == "testing");
-    }
-#ifndef TEST_HAS_NO_WIDE_CHARACTERS
-    {
-        std::wstringbuf buf1(L"testing");
-        std::wstringbuf buf;
-        buf = std::move(buf1);
-        assert(buf.str() == L"testing");
-    }
-    {
-        std::wstringbuf buf1(L"testing", std::ios_base::in);
-        std::wstringbuf buf;
-        buf = std::move(buf1);
-        assert(buf.str() == L"testing");
-    }
-    {
-        std::wstringbuf buf1(L"testing", std::ios_base::out);
-        std::wstringbuf buf;
-        buf = std::move(buf1);
-        assert(buf.str() == L"testing");
-    }
-#endif // TEST_HAS_NO_WIDE_CHARACTERS
+#define STR(S) MAKE_STRING(CharT, S)
+
+template <class CharT>
+struct test_stringbuf : std::basic_stringbuf<CharT> {
+  using std::basic_stringbuf<CharT>::basic_stringbuf;
+  void check() {
+    assert(this->eback() == nullptr);
+    assert(this->gptr() == nullptr);
+    assert(this->egptr() == nullptr);
+    assert(this->pbase() == nullptr);
+    assert(this->pptr() == nullptr);
+    assert(this->epptr() == nullptr);
+  }
+};
 
+template <class CharT>
+static void test() {
+  {
+    test_stringbuf<CharT> buf1(STR("testing"));
+    std::basic_stringbuf<CharT> buf;
+    buf = std::move(buf1);
+    assert(buf.str() == STR("testing"));
+    buf1.check();
+  }
+  {
+    test_stringbuf<CharT> buf1(STR("testing"), std::ios_base::in);
+    std::basic_stringbuf<CharT> buf;
+    buf = std::move(buf1);
+    assert(buf.str() == STR("testing"));
+    buf1.check();
+  }
+  {
+    test_stringbuf<CharT> buf1(STR("testing"), std::ios_base::out);
+    std::basic_stringbuf<CharT> buf;
+    buf = std::move(buf1);
+    assert(buf.str() == STR("testing"));
+    buf1.check();
+  }
+}
+
+int main(int, char**) {
+  test<char>();
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+  test<wchar_t>();
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.alloc.pass.cpp b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.alloc.pass.cpp
--- a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.alloc.pass.cpp
+++ b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.alloc.pass.cpp
@@ -25,13 +25,27 @@
 #define STR(S) MAKE_STRING(CharT, S)
 #define SV(S) MAKE_STRING_VIEW(CharT, S)
 
+template <class CharT>
+struct test_stringbuf : std::basic_stringbuf<CharT, std::char_traits<CharT>, test_allocator<CharT>> {
+  using std::basic_stringbuf<CharT, std::char_traits<CharT>, test_allocator<CharT>>::basic_stringbuf;
+  void check() {
+    assert(this->eback() == nullptr);
+    assert(this->gptr() == nullptr);
+    assert(this->egptr() == nullptr);
+    assert(this->pbase() == nullptr);
+    assert(this->pptr() == nullptr);
+    assert(this->epptr() == nullptr);
+  }
+};
+
 template <class CharT>
 static void test() {
-  std::basic_stringbuf<CharT, std::char_traits<CharT>, test_allocator<CharT>> buf1(STR("testing"));
+  test_stringbuf<CharT> buf1(STR("testing"));
   const test_allocator<CharT> a(2);
   const std::basic_stringbuf<CharT, std::char_traits<CharT>, test_allocator<CharT>> buf(std::move(buf1), a);
   assert(buf.get_allocator() == a);
   assert(buf.view() == SV("testing"));
+  buf1.check();
 }
 
 int main(int, char**) {
diff --git a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.pass.cpp b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.pass.cpp
--- a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.pass.cpp
+++ b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.cons/move.pass.cpp
@@ -16,42 +16,50 @@
 #include <sstream>
 #include <cassert>
 
+#include "make_string.h"
 #include "test_macros.h"
 
-int main(int, char**)
-{
-    {
-        std::stringbuf buf1("testing");
-        std::stringbuf buf(std::move(buf1));
-        assert(buf.str() == "testing");
-    }
-    {
-        std::stringbuf buf1("testing", std::ios_base::in);
-        std::stringbuf buf(std::move(buf1));
-        assert(buf.str() == "testing");
-    }
-    {
-        std::stringbuf buf1("testing", std::ios_base::out);
-        std::stringbuf buf(std::move(buf1));
-        assert(buf.str() == "testing");
-    }
+#define STR(S) MAKE_STRING(CharT, S)
+
+template <class CharT>
+struct test_stringbuf : std::basic_stringbuf<CharT> {
+  using std::basic_stringbuf<CharT>::basic_stringbuf;
+  void check() {
+    assert(this->eback() == nullptr);
+    assert(this->gptr() == nullptr);
+    assert(this->egptr() == nullptr);
+    assert(this->pbase() == nullptr);
+    assert(this->pptr() == nullptr);
+    assert(this->epptr() == nullptr);
+  }
+};
+
+template <class CharT>
+static void test() {
+  {
+    test_stringbuf<CharT> buf1(STR("testing"));
+    std::basic_stringbuf<CharT> buf(std::move(buf1));
+    assert(buf.str() == STR("testing"));
+    buf1.check();
+  }
+  {
+    test_stringbuf<CharT> buf1(STR("testing"), std::ios_base::in);
+    std::basic_stringbuf<CharT> buf(std::move(buf1));
+    assert(buf.str() == STR("testing"));
+    buf1.check();
+  }
+  {
+    test_stringbuf<CharT> buf1(STR("testing"), std::ios_base::out);
+    std::basic_stringbuf<CharT> buf(std::move(buf1));
+    assert(buf.str() == STR("testing"));
+    buf1.check();
+  }
+}
+
+int main(int, char**) {
+  test<char>();
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
-    {
-        std::wstringbuf buf1(L"testing");
-        std::wstringbuf buf(std::move(buf1));
-        assert(buf.str() == L"testing");
-    }
-    {
-        std::wstringbuf buf1(L"testing", std::ios_base::in);
-        std::wstringbuf buf(std::move(buf1));
-        assert(buf.str() == L"testing");
-    }
-    {
-        std::wstringbuf buf1(L"testing", std::ios_base::out);
-        std::wstringbuf buf(std::move(buf1));
-        assert(buf.str() == L"testing");
-    }
+  test<wchar_t>();
 #endif
-
   return 0;
 }