diff --git a/include/linux/can.h b/include/linux/can.h
index 2b7d511..de5e531 100644
--- a/include/linux/can.h
+++ b/include/linux/can.h
@@ -218,10 +218,10 @@ struct canxl_frame {
 	__u8    data[CANXL_MAX_DLEN];
 };
 
-#define CAN_MTU		(sizeof(struct can_frame))
-#define CANFD_MTU	(sizeof(struct canfd_frame))
-#define CANXL_MTU	(sizeof(struct canxl_frame))
-#define CANXL_HDR_SIZE	(offsetof(struct canxl_frame, data))
+#define CAN_MTU		(int)(sizeof(struct can_frame))
+#define CANFD_MTU	(int)(sizeof(struct canfd_frame))
+#define CANXL_MTU	(int)(sizeof(struct canxl_frame))
+#define CANXL_HDR_SIZE	(int)(offsetof(struct canxl_frame, data))
 #define CANXL_MIN_MTU	(CANXL_HDR_SIZE + 64)
 #define CANXL_MAX_MTU	CANXL_MTU
 
diff --git a/lib.c b/lib.c
index 1c2ec0c..0ea46e6 100644
--- a/lib.c
+++ b/lib.c
@@ -522,7 +522,7 @@ int snprintf_long_canframe(char *buf, size_t size, cu_t *cu, int view)
 		}
 	}
 
-	if (maxsize > size - 1) {
+	if (maxsize > (int)size - 1) {
 		/* mark buffer overflow in output */
 		memset(buf, '-', size - 1);
 		buf[size - 1] = 0;