diff --git a/src/tls/BearSSLClient.h b/src/tls/BearSSLClient.h
index ff60214db..457ef92f0 100644
--- a/src/tls/BearSSLClient.h
+++ b/src/tls/BearSSLClient.h
@@ -90,9 +90,8 @@ class BearSSLClient : public Client {
   Client* _client;
   const br_x509_trust_anchor* _TAs;
   int _numTAs;
-  GetTimeCallbackFunc _get_time_func;
-
   bool _noSNI;
+  GetTimeCallbackFunc _get_time_func;
 
   br_ec_private_key _ecKey;
   br_x509_certificate _ecCert;
diff --git a/src/tls/profile/aiotc_profile.c b/src/tls/profile/aiotc_profile.c
index 2e2fa7372..e546b7577 100644
--- a/src/tls/profile/aiotc_profile.c
+++ b/src/tls/profile/aiotc_profile.c
@@ -51,8 +51,6 @@ void aiotc_client_profile_init(br_ssl_client_context *cc, br_x509_minimal_contex
     BR_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
   };
 
-  int id;
-
   /*
    * Reset client context and set supported versions from TLS-1.0
    * to TLS-1.2 (inclusive).
diff --git a/src/tls/utility/Cert.h b/src/tls/utility/Cert.h
index 45f531869..9a74ea35b 100644
--- a/src/tls/utility/Cert.h
+++ b/src/tls/utility/Cert.h
@@ -147,12 +147,12 @@ class ArduinoIoTCloudCertClass {
     byte data[CERT_COMPRESSED_CERT_SLOT_LENGTH + CERT_SERIAL_NUMBER_LENGTH + CERT_AUTHORITY_KEY_ID_LENGTH];
   } _compressedCert;
 
-  /* only raw EC X Y values 64 byte */
-  const byte * _publicKey;
-
   byte * _certBuffer;
   int    _certBufferLen;
 
+  /* only raw EC X Y values 64 byte */
+  const byte * _publicKey;
+
   int versionLength();
   int issuerOrSubjectLength(const CertInfo& issuerOrSubjectData);
   int sequenceHeaderLength(int length);
diff --git a/src/utility/ota/OTA-samd.cpp b/src/utility/ota/OTA-samd.cpp
index dc5e1cc1f..da4a98e27 100644
--- a/src/utility/ota/OTA-samd.cpp
+++ b/src/utility/ota/OTA-samd.cpp
@@ -57,7 +57,12 @@ int samd_onOTARequest(char const * ota_url)
 
   /* Perform the reset to reboot to SxU. */
   NVIC_SystemReset();
+
+  return static_cast<int>(OTAError::None);
 #endif /* OTA_STORAGE_SNU */
+
+  (void)ota_url;
+  return static_cast<int>(OTAError::DownloadFailed);
 }
 
 #endif /* ARDUINO_ARCH_SAMD */
diff --git a/src/utility/time/NTPUtils.h b/src/utility/time/NTPUtils.h
index 91cec89af..6337015a5 100644
--- a/src/utility/time/NTPUtils.h
+++ b/src/utility/time/NTPUtils.h
@@ -54,7 +54,7 @@ class NTPUtils
   static int           const MAX_NTP_PORT         = 65535;
 #endif
   static unsigned long const NTP_TIMEOUT_MS       = 1000;
-  static char constexpr *    NTP_TIME_SERVER      = "time.arduino.cc";
+  static constexpr const char * NTP_TIME_SERVER   = "time.arduino.cc";
 
   static void sendNTPpacket(UDP & udp);
 };
diff --git a/src/utility/watchdog/Watchdog.cpp b/src/utility/watchdog/Watchdog.cpp
index a45f02d4e..21cf7374c 100644
--- a/src/utility/watchdog/Watchdog.cpp
+++ b/src/utility/watchdog/Watchdog.cpp
@@ -173,6 +173,7 @@ void watchdog_reset()
 void watchdog_enable_network_feed(const bool use_ethernet)
 {
 #ifdef WIFI_HAS_FEED_WATCHDOG_FUNC
+  (void)use_ethernet;
   WiFi.setFeedWatchdogFunc(watchdog_reset);
 #endif