diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -613,28 +613,14 @@
 _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS string operator+<char, char_traits<char>, allocator<char> >(char const*, string const&))
 
 template <bool>
-class _LIBCPP_TEMPLATE_VIS __basic_string_common
-{
-protected:
-    _LIBCPP_NORETURN void __throw_length_error() const;
-    _LIBCPP_NORETURN void __throw_out_of_range() const;
-};
-
-template <bool __b>
-void
-__basic_string_common<__b>::__throw_length_error() const
-{
-    _VSTD::__throw_length_error("basic_string");
-}
+struct __basic_string_common;
 
-template <bool __b>
-void
-__basic_string_common<__b>::__throw_out_of_range() const
-{
-    _VSTD::__throw_out_of_range("basic_string");
-}
-
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __basic_string_common<true>)
+template <>
+struct __basic_string_common<true> {
+    // Both are defined in string.cpp
+    _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_length_error() const;
+    _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_out_of_range() const;
+};
 
 template <class _Iter>
 struct __string_is_trivial_iterator : public false_type {};
@@ -688,7 +674,6 @@
     _LIBCPP_PREFERRED_NAME(u32string)
 #endif
     basic_string
-    : private __basic_string_common<true>
 {
 public:
     typedef basic_string                                 __self;
@@ -1718,7 +1703,7 @@
     _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI
     void __throw_length_error() const {
 #ifndef _LIBCPP_NO_EXCEPTIONS
-        __basic_string_common<true>::__throw_length_error();
+        __basic_string_common<true>().__throw_length_error();
 #else
         _VSTD::abort();
 #endif
@@ -1727,7 +1712,7 @@
     _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI
     void __throw_out_of_range() const {
 #ifndef _LIBCPP_NO_EXCEPTIONS
-        __basic_string_common<true>::__throw_out_of_range();
+        __basic_string_common<true>().__throw_out_of_range();
 #else
         _VSTD::abort();
 #endif
diff --git a/libcxx/include/vector b/libcxx/include/vector
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -302,33 +302,17 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <bool>
-class _LIBCPP_TEMPLATE_VIS __vector_base_common
-{
-protected:
-    _LIBCPP_INLINE_VISIBILITY __vector_base_common() {}
-    _LIBCPP_NORETURN void __throw_length_error() const;
-    _LIBCPP_NORETURN void __throw_out_of_range() const;
-};
-
-template <bool __b>
-void
-__vector_base_common<__b>::__throw_length_error() const
-{
-    _VSTD::__throw_length_error("vector");
-}
-
-template <bool __b>
-void
-__vector_base_common<__b>::__throw_out_of_range() const
-{
-    _VSTD::__throw_out_of_range("vector");
-}
+struct __vector_base_common;
 
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __vector_base_common<true>)
+template <>
+struct __vector_base_common<true> {
+    // Both are defined in vector.cpp
+    _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_length_error() const;
+    _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_out_of_range() const;
+};
 
 template <class _Tp, class _Allocator>
 class __vector_base
-    : protected __vector_base_common<true>
 {
 public:
     typedef _Allocator                               allocator_type;
@@ -395,7 +379,7 @@
     _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI
     void __throw_length_error() const {
 #ifndef _LIBCPP_NO_EXCEPTIONS
-        __vector_base_common<true>::__throw_length_error();
+        __vector_base_common<true>().__throw_length_error();
 #else
         _VSTD::abort();
 #endif
@@ -404,7 +388,7 @@
     _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI
     void __throw_out_of_range() const {
 #ifndef _LIBCPP_NO_EXCEPTIONS
-        __vector_base_common<true>::__throw_out_of_range();
+        __vector_base_common<true>().__throw_out_of_range();
 #else
         _VSTD::abort();
 #endif
diff --git a/libcxx/src/string.cpp b/libcxx/src/string.cpp
--- a/libcxx/src/string.cpp
+++ b/libcxx/src/string.cpp
@@ -18,7 +18,13 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template class _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS __basic_string_common<true>;
+void __basic_string_common<true>::__throw_length_error() const {
+    _VSTD::__throw_length_error("basic_string");
+}
+
+void __basic_string_common<true>::__throw_out_of_range() const {
+    _VSTD::__throw_out_of_range("basic_string");
+}
 
 #define _LIBCPP_EXTERN_TEMPLATE_DEFINE(...) template __VA_ARGS__;
 #ifdef _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
diff --git a/libcxx/src/vector.cpp b/libcxx/src/vector.cpp
--- a/libcxx/src/vector.cpp
+++ b/libcxx/src/vector.cpp
@@ -10,6 +10,12 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template class _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS __vector_base_common<true>;
+void __vector_base_common<true>::__throw_length_error() const {
+    _VSTD::__throw_length_error("vector");
+}
+
+void __vector_base_common<true>::__throw_out_of_range() const {
+    _VSTD::__throw_out_of_range("vector");
+}
 
 _LIBCPP_END_NAMESPACE_STD