diff --git a/src/mqtt.cpp b/src/mqtt.cpp
index 4a5b37c..5af7c10 100644
--- a/src/mqtt.cpp
+++ b/src/mqtt.cpp
@@ -85,6 +85,7 @@ void mqttLoop() {
     if (mqttLast == 0 || millis() - mqttLast >= 3000) {
       mqttLast = max(1UL, millis());
       client.setServer(mqttHost.c_str(), mqttPort);
+      client.setBufferSize(512);
       Serial.printf("[MQTT] Connecting: %s:%ld\n", mqttHost.c_str(), mqttPort);
       if (client.connect(WiFi.getHostname(), mqttUser.c_str(), mqttPass.c_str())) {
         Serial.printf("[MQTT] Connected.\n");
@@ -106,9 +107,9 @@ void mqttPublish(const String &topic, const JsonDocument &json) {
   if (!mqttShouldConnect) {
     return;
   }
-  char buffer[256];
-  const auto size = serializeJson(json, buffer);
-  client.publish(topic.c_str(), buffer, size);
+  char buffer[512];
+  serializeJson(json, buffer);
+  client.publish(topic.c_str(), buffer);
 }
 
 String getMqttUser() {