--- a/lib/getlocalename_l-unsafe.c
+++ b/lib/getlocalename_l-unsafe.c
@@ -658,9 +658,10 @@ getlocalename_l_unsafe (int category, locale_t locale)
       };
       const char *name = ((struct __locale_t *) locale)->mb_cur_max == 4 ? "C.UTF-8" : "C";
       return (struct string_with_storage) { name, STORAGE_INDEFINITE };
-#elif defined __redox__ && HAVE_GETLOCALENAME_L
-      const char *name = getlocalename_l (category, locale);
-      return (struct string_with_storage) { name != NULL ? name : "", STORAGE_OBJECT };
+#elif defined __redox__ && !HAVE_GETLOCALENAME_L
+      /* Redox's relibc has no getlocalename_l; return the closest matching
+         POSIX locale name without referencing a non-existent symbol. */
+      return (struct string_with_storage) { "C", STORAGE_INDEFINITE };
 #else
  #error "Please port gnulib getlocalename_l-unsafe.c to your platform! Report this to bug-gnulib."
 #endif