diff --git a/byte_order_stuff.cpp b/byte_order_stuff.cpp
index 6f204d6..3ee9070 100644
--- a/byte_order_stuff.cpp
+++ b/byte_order_stuff.cpp
@@ -72,6 +72,14 @@ void data_streamer::putsi24(int32_t val, std::ostream& file) const {
 	putui24(static_cast<uint32_t>(val), file);
 }
 
+void data_streamer::putf80(double val, std::ostream& file) const {
+	float_80 f80 {val};
+	if (_target_byte_order != byte_order::big_endian) {
+		byte_swap(f80._val, sizeof(f80._val));
+	}
+	file.write(reinterpret_cast<char*>(f80._val), sizeof(f80._val));
+}
+
 // byte_order_changer ----------------------------------------------------------
 
 byte_order_changer::byte_order_changer(data_streamer* ds, byte_order order) : _data_streamer {ds} {