# define STRTOD_L strtod_l
#endif
-/* c_strtold falls back on strtod if strtold isn't declared. */
-#if LONG && HAVE_DECL_STRTOLD
+/* c_strtold falls back on strtod if strtold doesn't conform to C99. */
+#if LONG && HAVE_C99_STRTOLD
# define STRTOD strtold
#else
# define STRTOD strtod