diff --git a/src/apps/mqtt/mqtt.c b/src/apps/mqtt/mqtt.c
index c09642be..096215e2 100644
--- a/src/apps/mqtt/mqtt.c
+++ b/src/apps/mqtt/mqtt.c
@@ -711,7 +711,7 @@ mqtt_message_received(mqtt_client_t *client, u8_t fixed_hdr_len, u16_t length, u
     u16_t payload_length = length;
     u8_t qos = MQTT_CTL_PACKET_QOS(client->rx_buffer[0]);
 
-    if (client->msg_idx == (fixed_hdr_len + length)) {
+    if (client->msg_idx == (u32_t)(fixed_hdr_len + length)) {
       /* First publish message frame. Should have topic and pkt id*/
       size_t var_hdr_payload_bufsize = sizeof(client->rx_buffer) - fixed_hdr_len;
       u8_t *topic;