diff --git a/src/protocol/codec/serial.c b/src/protocol/codec/serial.c
index b5c0e0b4a..76356ecdd 100644
--- a/src/protocol/codec/serial.c
+++ b/src/protocol/codec/serial.c
@@ -12,6 +12,7 @@
 //   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
 //
 
+#include <inttypes.h>
 #include <stdint.h>
 #include <string.h>
 
@@ -108,7 +109,7 @@ size_t _z_serial_msg_deserialize(const uint8_t *src, size_t src_len, uint8_t *ds
 
     uint32_t computed_crc = _z_crc32(dst, wire_size);
     if (received_crc != computed_crc) {
-        _Z_DEBUG("CRC mismatch. Received: 0x%08lX, Computed: 0x%08lX", received_crc, computed_crc);
+        _Z_DEBUG("CRC mismatch. Received: 0x%08" PRIu32 ", Computed: 0x%08" PRIu32, received_crc, computed_crc);
         return SIZE_MAX;
     }
 
diff --git a/src/system/common/serial.c b/src/system/common/serial.c
index 2104818ea..80c626b35 100644
--- a/src/system/common/serial.c
+++ b/src/system/common/serial.c
@@ -12,10 +12,11 @@
 //   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
 //
 
-#include "zenoh-pico/protocol/definitions/serial.h"
-
 #include <stdint.h>
 
+#if Z_FEATURE_LINK_SERIAL == 1
+
+#include "zenoh-pico/protocol/definitions/serial.h"
 #include "zenoh-pico/system/common/platform.h"
 #include "zenoh-pico/system/common/serial.h"
 #include "zenoh-pico/system/link/serial.h"
@@ -30,8 +31,7 @@ z_result_t _z_connect_serial(const _z_sys_net_socket_t sock) {
         uint8_t header = _Z_FLAG_SERIAL_INIT;
 
         _z_send_serial_internal(sock, header, NULL, 0);
-        uint8_t tmp;
-        size_t ret = _z_read_serial_internal(sock, &header, &tmp, sizeof(tmp));
+        size_t ret = _z_read_serial_internal(sock, &header, NULL, 0);
         if (ret == SIZE_MAX) {
             return _Z_ERR_TRANSPORT_RX_FAILED;
         }
@@ -78,3 +78,4 @@ size_t _z_read_exact_serial(const _z_sys_net_socket_t sock, uint8_t *ptr, size_t
 
     return n;
 }
+#endif  // Z_FEATURE_LINK_SERIAL == 1
diff --git a/tests/z_msgcodec_test.c b/tests/z_msgcodec_test.c
index fd827c620..982721a69 100644
--- a/tests/z_msgcodec_test.c
+++ b/tests/z_msgcodec_test.c
@@ -1985,13 +1985,13 @@ void test_serialize_deserialize() {
     uint8_t deserialized[256] = {0};
     uint8_t tmp_buf[256] = {0};
 
-    int serialized_len =
+    size_t serialized_len =
         _z_serial_msg_serialize(serialized, sizeof(serialized), src_data, src_len, header, tmp_buf, sizeof(tmp_buf));
     assert(serialized_len > 0);
 
     uint8_t decoded_header = 0;
-    int deserialized_len = _z_serial_msg_deserialize(serialized, serialized_len, deserialized, sizeof(deserialized),
-                                                     &decoded_header, tmp_buf, sizeof(tmp_buf));
+    size_t deserialized_len = _z_serial_msg_deserialize(serialized, serialized_len, deserialized, sizeof(deserialized),
+                                                        &decoded_header, tmp_buf, sizeof(tmp_buf));
     assert(deserialized_len != SIZE_MAX);
 
     assert(decoded_header == header);
@@ -2007,7 +2007,7 @@ void test_crc_mismatch() {
     uint8_t serialized[256] = {0};
     uint8_t tmp_buf[256] = {0};
 
-    int serialized_len =
+    size_t serialized_len =
         _z_serial_msg_serialize(serialized, sizeof(serialized), src_data, src_len, header, tmp_buf, sizeof(tmp_buf));
     assert(serialized_len != SIZE_MAX);
 
@@ -2015,8 +2015,8 @@ void test_crc_mismatch() {
 
     uint8_t decoded_header = 0;
     uint8_t deserialized[256] = {0};
-    int deserialized_len = _z_serial_msg_deserialize(serialized, serialized_len, deserialized, sizeof(deserialized),
-                                                     &decoded_header, tmp_buf, sizeof(tmp_buf));
+    size_t deserialized_len = _z_serial_msg_deserialize(serialized, serialized_len, deserialized, sizeof(deserialized),
+                                                        &decoded_header, tmp_buf, sizeof(tmp_buf));
 
     assert(deserialized_len == SIZE_MAX);
 }
@@ -2028,14 +2028,14 @@ void test_buffer_too_small() {
     uint8_t serialized[256] = {0};
     uint8_t tmp_buf[256] = {0};
 
-    int serialized_len =
+    size_t serialized_len =
         _z_serial_msg_serialize(serialized, sizeof(serialized), src_data, src_len, header, tmp_buf, sizeof(tmp_buf));
     assert(serialized_len != SIZE_MAX);
 
     uint8_t decoded_header = 0;
     uint8_t deserialized[4] = {0};  // Too small
-    int deserialized_len = _z_serial_msg_deserialize(serialized, serialized_len, deserialized, sizeof(deserialized),
-                                                     &decoded_header, tmp_buf, sizeof(tmp_buf));
+    size_t deserialized_len = _z_serial_msg_deserialize(serialized, serialized_len, deserialized, sizeof(deserialized),
+                                                        &decoded_header, tmp_buf, sizeof(tmp_buf));
 
     assert(deserialized_len == SIZE_MAX);
 }