diff --git a/boot/boot_serial/src/boot_serial.c b/boot/boot_serial/src/boot_serial.c
index 3fded86..9f9cd15 100644
--- a/boot/boot_serial/src/boot_serial.c
+++ b/boot/boot_serial/src/boot_serial.c
@@ -485,7 +485,7 @@
     bs_hdr->nh_group = htons(bs_hdr->nh_group);
 
 #ifdef __ZEPHYR__
-    crc =  crc16((u8_t *)bs_hdr, sizeof(*bs_hdr), CRC_CITT_POLYMINAL,
+    crc =  crc16((uint8_t *)bs_hdr, sizeof(*bs_hdr), CRC_CITT_POLYMINAL,
                  CRC16_INITIAL_CRC, false);
     crc =  crc16(data, len, CRC_CITT_POLYMINAL, crc, true);
 #else