diff --git a/pymavlink/generator/C/include_v0.9/mavlink_helpers.h b/pymavlink/generator/C/include_v0.9/mavlink_helpers.h
index b53a5ee34d..3e2058feae 100644
--- a/pymavlink/generator/C/include_v0.9/mavlink_helpers.h
+++ b/pymavlink/generator/C/include_v0.9/mavlink_helpers.h
@@ -227,6 +227,13 @@ MAVLINK_HELPER uint8_t mavlink_parse_char(uint8_t chan, uint8_t c, mavlink_messa
 	static const uint8_t mavlink_message_crcs[256] = MAVLINK_MESSAGE_CRCS;
 #define MAVLINK_MESSAGE_CRC(msgid) mavlink_message_crcs[msgid]
 #endif
+#endif
+
+#if MAVLINK_CHECK_MESSAGE_LENGTH
+#ifndef MAVLINK_MESSAGE_LENGTH
+	static const uint8_t mavlink_message_lengths[256] = MAVLINK_MESSAGE_LENGTHS;
+#define MAVLINK_MESSAGE_LENGTH(msgid) mavlink_message_lengths[msgid]
+#endif
 #endif
 
 	mavlink_message_t* rxmsg = mavlink_get_channel_buffer(chan); ///< The currently decoded message
@@ -291,6 +298,19 @@ MAVLINK_HELPER uint8_t mavlink_parse_char(uint8_t chan, uint8_t c, mavlink_messa
 		break;
 
 	case MAVLINK_PARSE_STATE_GOT_COMPID:
+#if MAVLINK_CHECK_MESSAGE_LENGTH
+	        if (rxmsg->len != MAVLINK_MESSAGE_LENGTH(c))
+		{
+			status->parse_error++;
+			status->parse_state = MAVLINK_PARSE_STATE_IDLE;
+			break;
+			if (c == MAVLINK_STX)
+			{
+				status->parse_state = MAVLINK_PARSE_STATE_GOT_STX;
+				mavlink_start_checksum(rxmsg);
+			}
+	        }
+#endif
 		rxmsg->msgid = c;
 		mavlink_update_checksum(rxmsg, c);
 		if (rxmsg->len == 0)
diff --git a/pymavlink/generator/C/include_v1.0/mavlink_helpers.h b/pymavlink/generator/C/include_v1.0/mavlink_helpers.h
index b53a5ee34d..3e2058feae 100644
--- a/pymavlink/generator/C/include_v1.0/mavlink_helpers.h
+++ b/pymavlink/generator/C/include_v1.0/mavlink_helpers.h
@@ -227,6 +227,13 @@ MAVLINK_HELPER uint8_t mavlink_parse_char(uint8_t chan, uint8_t c, mavlink_messa
 	static const uint8_t mavlink_message_crcs[256] = MAVLINK_MESSAGE_CRCS;
 #define MAVLINK_MESSAGE_CRC(msgid) mavlink_message_crcs[msgid]
 #endif
+#endif
+
+#if MAVLINK_CHECK_MESSAGE_LENGTH
+#ifndef MAVLINK_MESSAGE_LENGTH
+	static const uint8_t mavlink_message_lengths[256] = MAVLINK_MESSAGE_LENGTHS;
+#define MAVLINK_MESSAGE_LENGTH(msgid) mavlink_message_lengths[msgid]
+#endif
 #endif
 
 	mavlink_message_t* rxmsg = mavlink_get_channel_buffer(chan); ///< The currently decoded message
@@ -291,6 +298,19 @@ MAVLINK_HELPER uint8_t mavlink_parse_char(uint8_t chan, uint8_t c, mavlink_messa
 		break;
 
 	case MAVLINK_PARSE_STATE_GOT_COMPID:
+#if MAVLINK_CHECK_MESSAGE_LENGTH
+	        if (rxmsg->len != MAVLINK_MESSAGE_LENGTH(c))
+		{
+			status->parse_error++;
+			status->parse_state = MAVLINK_PARSE_STATE_IDLE;
+			break;
+			if (c == MAVLINK_STX)
+			{
+				status->parse_state = MAVLINK_PARSE_STATE_GOT_STX;
+				mavlink_start_checksum(rxmsg);
+			}
+	        }
+#endif
 		rxmsg->msgid = c;
 		mavlink_update_checksum(rxmsg, c);
 		if (rxmsg->len == 0)