diff --git a/isotprecv.c b/isotprecv.c
index 406cf5d..d5adb96 100644
--- a/isotprecv.c
+++ b/isotprecv.c
@@ -55,6 +55,7 @@
 
 #include <linux/can.h>
 #include <linux/can/isotp.h>
+#include <errno.h>
 
 #define NO_CAN_ID 0xFFFFFFFFU
 #define BUFSIZE 5000 /* size > 4095 to check socket API internal checks */
@@ -243,6 +244,7 @@ int main(int argc, char **argv)
 
     do {
 	    nbytes = read(s, msg, BUFSIZE);
+	    printf("received %d, %d", nbytes, errno);
 	    if (nbytes > 0 && nbytes < BUFSIZE)
 		    for (i=0; i < nbytes; i++)
 			    printf("%02X ", msg[i]);