diff --git a/src/modules/mavlink/mavlink_ftp.cpp b/src/modules/mavlink/mavlink_ftp.cpp
index b847fc6258..a5c96274be 100644
--- a/src/modules/mavlink/mavlink_ftp.cpp
+++ b/src/modules/mavlink/mavlink_ftp.cpp
@@ -247,9 +247,8 @@ MavlinkFTP::_reply(Request *req)
 	PayloadHeader *payload = reinterpret_cast<PayloadHeader *>(&req->message.payload[0]);
 	
 	payload->seqNumber = payload->seqNumber + 1;
-	payload->reserved[0] = 0;
-	payload->reserved[1] = 0;
-	payload->reserved[2] = 0;
+	payload->padding[0] = 0;
+	payload->padding[1] = 0;
 
 	mavlink_message_t msg;
 	msg.checksum = 0;
diff --git a/src/modules/mavlink/mavlink_ftp.h b/src/modules/mavlink/mavlink_ftp.h
index ae7955ab73..4892e548c0 100644
--- a/src/modules/mavlink/mavlink_ftp.h
+++ b/src/modules/mavlink/mavlink_ftp.h
@@ -77,7 +77,7 @@ public:
 		uint8_t		opcode;		///< Command opcode
 		uint8_t		size;		///< Size of data
 		uint8_t		req_opcode;	///< Request opcode returned in kRspAck, kRspNak message
-		uint16_t	reserved[3];	///< reserved area
+		uint8_t		padding[2];	///< 32 bit aligment padding
 		uint32_t	offset;		///< Offsets for List and Read commands
 		uint8_t		data[];		///< command data, varies by Opcode
         };