diff --git a/library.json b/library.json
index 90d5b6a..13961ca 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "LMICPP-Arduino",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "keywords": "Lora",
   "description": "Modified Arduino port of the LMIC (LoraWAN-in-C, formerly LoraMAC-in-C) framework provided by IBM. Changed to C++ format.",
   "frameworks": ["arduino"],
diff --git a/library.properties b/library.properties
index 9881983..b5e1ad3 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=LMICPP-Arduino
-version=2.3.0
+version=2.3.1
 author=IBM
 maintainer=Nicolas Graziano <nicolas.graziano@gmail.com>
 sentence=Modified Arduino port of the LMIC (LoraWAN-in-C, formerly LoraMAC-in-C) framework provided by IBM. Changed to C++ format.
diff --git a/platformio.ini b/platformio.ini
index 4c686fb..5735e96 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -19,7 +19,7 @@ upload_speed = 9600
 #upload_speed = 57600
 upload_port = COM3
 # test_port= COM3
-# test_speed=57600
+test_speed=9600
 
 monitor_port = COM3
 monitor_speed = 9600
diff --git a/src/aes/limc_aes.cpp b/src/aes/limc_aes.cpp
index 0b7adcf..b68b9ae 100644
--- a/src/aes/limc_aes.cpp
+++ b/src/aes/limc_aes.cpp
@@ -79,7 +79,8 @@ void Aes::appendMic(const uint32_t devaddr, const uint32_t seqno,
  * len : total length (MIC included)
  */
 void Aes::appendMic0(uint8_t *const pdu, const uint8_t len) const {
-  AesBlock buf = {0};
+  AesBlock buf;
+  buf.fill(0);
   const uint8_t lenWithoutMic = len - lengths::MIC;
   aes_cmac(pdu, lenWithoutMic, false, AESDevKey, buf);
   // Copy MIC0 at the end
@@ -91,7 +92,8 @@ void Aes::appendMic0(uint8_t *const pdu, const uint8_t len) const {
  * len : total length (MIC included)
  */
 bool Aes::verifyMic0(const uint8_t *const pdu, const uint8_t len) const {
-  AesBlock buf = {0};
+  AesBlock buf;
+  buf.fill(0);
   const uint8_t lenWithoutMic = len - lengths::MIC;
   aes_cmac(pdu, lenWithoutMic, false, AESDevKey, buf);
   return std::equal(buf.begin(), buf.begin() + lengths::MIC,
@@ -202,8 +204,9 @@ void Aes::aes_cmac(const uint8_t *buf, uint8_t len, const bool prepend_aux,
       // Final block, xor with K1 or K2. K1 and K2 are calculated
       // by encrypting the all-zeroes block and then applying some
       // shifts and xor on that.
-      AesBlock final_key = {0};
-      // std::fill(final_key, final_key + AES_BLCK_SIZE, 0);
+      AesBlock final_key;
+      std::fill_n(final_key.begin(), final_key.size(), 0);
+
       block_encrypt(final_key, key);
 
       // Calculate K1