diff --git a/FAQ.md b/FAQ.md
index 503b0ac..9536175 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -111,9 +111,11 @@ struct SensorData {
    float value;
 };
 
+#define SENSORDATA_JSON_SIZE (JSON_OBJECT_SIZE(3))
+
 bool deserialize(SensorData& data, const char* json)
 {
-    StaticJsonBuffer<200> jsonBuffer;
+    StaticJsonBuffer<SENSORDATA_JSON_SIZE> jsonBuffer;
     JsonObject& root = jsonBuffer.parseObject(json)
     data.name = json["name"];
     data.time = json["time"];
@@ -123,7 +125,7 @@ bool deserialize(SensorData& data, const char* json)
 
 void serialize(const SensorData& data, char* json, size_t maxSize)
 {
-    StaticJsonBuffer<200> jsonBuffer;
+    StaticJsonBuffer<SENSORDATA_JSON_SIZE> jsonBuffer;
     JsonObject& root = jsonBuffer.createObject()
     root["name"] = data.name;
     root["time"] = data.time;