diff --git a/firmware/main/app_main.cc b/firmware/main/app_main.cc
index 2d5fa35..2690185 100644
--- a/firmware/main/app_main.cc
+++ b/firmware/main/app_main.cc
@@ -92,7 +92,7 @@ struct PmMeasurementSum {
 
   void addMeasurement(const PmsResponse &resp);
   void reset();
-} __attribute__((packed));
+};
 
 enum class MeasurementType { MS_TEMPERATURE, MS_PARTICULATES };
 
@@ -745,10 +745,14 @@ static void initWifi() {
           .pmf_cfg{.capable = true, .required = false},
       },
   };
-  strncpy((char *)wf_conf.sta.ssid, appSettings.wifi.ssid,
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+  strncpy(reinterpret_cast<char *>(wf_conf.sta.ssid), appSettings.wifi.ssid,
           sizeof(wf_conf.sta.ssid));
-  strncpy((char *)wf_conf.sta.password, appSettings.wifi.pass,
+  strncpy(reinterpret_cast<char *>(wf_conf.sta.password), appSettings.wifi.pass,
           sizeof(wf_conf.sta.password));
+#pragma GCC diagnostic pop
 
   ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
   ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wf_conf));
diff --git a/firmware/main/timer.hh b/firmware/main/timer.hh
index 4e951ef..08c25c8 100644
--- a/firmware/main/timer.hh
+++ b/firmware/main/timer.hh
@@ -1,18 +1,25 @@
 #pragma once
 
 #include "freertos/FreeRTOS.h"
-#include <chrono>
+#include <numeric>
 
 class Timer {
 public:
   // creates and starts the timer
-  Timer() { ticks = xTaskGetTickCount(); }
+  Timer() { start = xTaskGetTickCount(); }
 
   // returns passed time in seconds
   TickType_t seconds() {
-    return (xTaskGetTickCount() - ticks) / configTICK_RATE_HZ;
+    const TickType_t now = xTaskGetTickCount();
+
+    const TickType_t passed =
+        now >= start
+            ? now - start
+            : std::numeric_limits<decltype(start)>::max() - start + now;
+
+    return passed / configTICK_RATE_HZ;
   }
 
 private:
-  TickType_t ticks;
+  TickType_t start;
 };