diff --git a/mock-api/server.js b/mock-api/server.js
index 215d50f08..5ade146ce 100644
--- a/mock-api/server.js
+++ b/mock-api/server.js
@@ -899,17 +899,17 @@ app.get(EMSESP_STATUS_ENDPOINT, (req, res) => {
 })
 app.post(EMSESP_DEVICEDATA_ENDPOINT, (req, res) => {
   const id = req.body.id
-  if (id == 1) {
+  if (id === 1) {
     const encoded = msgpack.encode(emsesp_devicedata_1)
     res.write(encoded, 'binary')
     res.end(null, 'binary')
   }
-  if (id == 2) {
+  if (id === 2) {
     const encoded = msgpack.encode(emsesp_devicedata_2)
     res.write(encoded, 'binary')
     res.end(null, 'binary')
   }
-  if (id == 3) {
+  if (id === 3) {
     const encoded = msgpack.encode(emsesp_devicedata_3)
     res.write(encoded, 'binary')
     res.end(null, 'binary')
diff --git a/src/helpers.cpp b/src/helpers.cpp
index 6504f04df..949326686 100644
--- a/src/helpers.cpp
+++ b/src/helpers.cpp
@@ -36,14 +36,14 @@ char * Helpers::hextoa(char * result, const uint8_t value) {
 #ifdef EMSESP_STANDALONE
 // special function to work outside of ESP's libraries
 char * Helpers::ultostr(char * ptr, uint32_t value, const uint8_t base) {
-    unsigned long t = 0, res = 0;
-    unsigned long tmp   = value;
-    int           count = 0;
-
     if (NULL == ptr) {
         return NULL;
     }
 
+    unsigned long t     = 0;
+    unsigned long tmp   = value;
+    int           count = 0;
+
     if (tmp == 0) {
         count++;
     }
@@ -57,6 +57,8 @@ char * Helpers::ultostr(char * ptr, uint32_t value, const uint8_t base) {
 
     *ptr = '\0';
 
+    unsigned long res = 0;
+
     do {
         res = value - base * (t = value / base);
         if (res < 10) {
diff --git a/src/mqtt.cpp b/src/mqtt.cpp
index 0d1ce33ac..0e3476a79 100644
--- a/src/mqtt.cpp
+++ b/src/mqtt.cpp
@@ -107,8 +107,8 @@ void Mqtt::register_command(const uint8_t device_type, const __FlashStringHelper
 
     // register the individual commands too (e.g. ems-esp/boiler/wwonetime)
     // https://github.com/emsesp/EMS-ESP32/issues/31
-    std::string topic(MQTT_TOPIC_MAX_SIZE, '\0');
     if (subscribe_format_ == Subscribe_Format::INDIVIDUAL_ALL_HC && ((flags & CommandFlag::MQTT_SUB_FLAG_HC) == CommandFlag::MQTT_SUB_FLAG_HC)) {
+        std::string topic(MQTT_TOPIC_MAX_SIZE, '\0');
         topic = cmd_topic + "/hc1/" + uuid::read_flash_string(cmd);
         queue_subscribe_message(topic);
         topic = cmd_topic + "/hc2/" + uuid::read_flash_string(cmd);
@@ -118,6 +118,7 @@ void Mqtt::register_command(const uint8_t device_type, const __FlashStringHelper
         topic = cmd_topic + "/hc4/" + uuid::read_flash_string(cmd);
         queue_subscribe_message(topic);
     } else if (subscribe_format_ != Subscribe_Format::GENERAL && ((flags & CommandFlag::MQTT_SUB_FLAG_NOSUB) == CommandFlag::MQTT_SUB_FLAG_NOSUB)) {
+        std::string topic(MQTT_TOPIC_MAX_SIZE, '\0');
         topic = cmd_topic + "/" + uuid::read_flash_string(cmd);
         queue_subscribe_message(topic);
     }