diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index f2570dc09..0993c1959 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -439,7 +439,7 @@ SPDLOG_INLINE bool in_terminal(FILE *file) SPDLOG_NOEXCEPT {
 
 #if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target) {
-    if (wstr.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) / 2 - 1) {
+    if (wstr.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) / 4 - 1) {
         throw_spdlog_ex("UTF-16 string is too big to be converted to UTF-8");
     }