diff --git a/libstdc++-v3/include/bits/cow_string.h b/libstdc++-v3/include/bits/cow_string.h
index 2298844f38d3812a40737e8662cb8d73431794cf..b78aa74fbfafed7af07e68f10f7a56e680256b30 100644
--- a/libstdc++-v3/include/bits/cow_string.h
+++ b/libstdc++-v3/include/bits/cow_string.h
@@ -3765,7 +3765,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _CharT, typename _Traits, typename _Alloc>
   template<typename _Operation>
     [[__gnu__::__always_inline__]]
-    void
+    inline void
     basic_string<_CharT, _Traits, _Alloc>::
     __resize_and_overwrite(const size_type __n, _Operation __op)
     { resize_and_overwrite<_Operation&>(__n, __op); }