diff --git a/src/os/windows/win32.h b/src/os/windows/win32.h
--- a/src/os/windows/win32.h
+++ b/src/os/windows/win32.h
@@ -59,6 +59,6 @@ char *convert_from_fs(const wchar_t *nam
 wchar_t *convert_to_fs(const std::string_view name, wchar_t *utf16_buf, size_t buflen);
 
 void Win32SetCurrentLocaleName(const char *iso_code);
-int OTTDStringCompare(const char *s1, const char *s2);
+int OTTDStringCompare(std::string_view s1, std::string_view s2);
 
 #endif /* WIN32_H */