diff --git a/lib/mqtt_msg.c b/lib/mqtt_msg.c
index 781bbea..4e9a2f4 100644
--- a/lib/mqtt_msg.c
+++ b/lib/mqtt_msg.c
@@ -619,7 +619,7 @@ int mqtt_has_valid_msg_hdr(uint8_t *buffer, size_t length)
 esp_err_t mqtt_msg_buffer_init(mqtt_connection_t *connection, int buffer_size)
 {
     memset(connection, 0, sizeof(mqtt_connection_t));
-    connection->buffer = (uint8_t *)calloc(0, buffer_size);
+    connection->buffer = (uint8_t *)calloc(buffer_size, sizeof(uint8_t));
     if (!connection->buffer) {
         return ESP_ERR_NO_MEM;
     }