diff --git a/Adafruit_MQTT.h b/Adafruit_MQTT.h
index 00657b4..76c4eb0 100644
--- a/Adafruit_MQTT.h
+++ b/Adafruit_MQTT.h
@@ -268,7 +268,8 @@ private:
   uint8_t connectPacket(uint8_t *packet);
   uint8_t disconnectPacket(uint8_t *packet);
   uint16_t publishPacket(uint8_t *packet, const char *topic, uint8_t *payload,
-                         uint16_t bLen, uint8_t qos, uint16_t maxPacketLen = 0);
+                         uint16_t bLen, uint8_t qos, uint16_t maxPacketLen = 0,
+                         bool retain = false);
   uint8_t subscribePacket(uint8_t *packet, const char *topic, uint8_t qos);
   uint8_t unsubscribePacket(uint8_t *packet, const char *topic);
   uint8_t pingPacket(uint8_t *packet);