diff --git a/phc2sys.c b/phc2sys.c
index cd91966..62248e7 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -85,7 +85,8 @@ static void clock_step(clockid_t clkid, int64_t ns)
 		fprintf(stderr, "failed to step clock: %m\n");
 }
 
-static int read_phc(clockid_t clkid, clockid_t sysclk, int rdelay, int readings, int64_t *offset, uint64_t *ts)
+static int read_phc(clockid_t clkid, clockid_t sysclk, int readings,
+		    int64_t *offset, uint64_t *ts)
 {
 	struct timespec tdst1, tdst2, tsrc;
 	int i;
@@ -106,8 +107,7 @@ static int read_phc(clockid_t clkid, clockid_t sysclk, int rdelay, int readings,
 		if (best_interval > interval) {
 			best_interval = interval;
 			*offset = (tdst1.tv_sec - tsrc.tv_sec) * NS_PER_SEC +
-				tdst1.tv_nsec - tsrc.tv_nsec +
-				interval / 2 - rdelay;
+				tdst1.tv_nsec - tsrc.tv_nsec + interval / 2;
 			*ts = tdst2.tv_sec * NS_PER_SEC + tdst2.tv_nsec;
 		}
 	}
@@ -199,7 +199,6 @@ static void usage(char *progname)
 		" -c [device]  slave clock device, default CLOCK_REALTIME\n"
 		" -d [device]  master device, source of PPS events\n"
 		" -h           prints this message and exits\n"
-		" -r [val]     reading the PHC device takes 'val' nanoseconds\n"
 		" -s [device]  set the time from this PHC device\n"
 		" -P [val]     set proportional constant to 'val'\n"
 		" -I [val]     set integration constant to 'val'\n"
@@ -216,12 +215,12 @@ int main(int argc, char *argv[])
 	clockid_t src = CLOCK_INVALID, dst = CLOCK_REALTIME;
 	uint64_t pps_ts, phc_ts;
 	int64_t pps_offset, phc_offset;
-	int c, fd = 0, rdelay = 0, phc_readings = 5, phc_rate = 1;
+	int c, fd = 0, phc_readings = 5, phc_rate = 1;
 
 	/* Process the command line arguments. */
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
-	while (EOF != (c = getopt(argc, argv, "c:d:hr:s:P:I:R:N:"))) {
+	while (EOF != (c = getopt(argc, argv, "c:d:hs:P:I:R:N:"))) {
 		switch (c) {
 		case 'c':
 			dst = clock_open(optarg);
@@ -229,9 +228,6 @@ int main(int argc, char *argv[])
 		case 'd':
 			device = optarg;
 			break;
-		case 'r':
-			rdelay = atoi(optarg);
-			break;
 		case 's':
 			src = clock_open(optarg);
 			break;
@@ -283,7 +279,7 @@ int main(int argc, char *argv[])
 			usleep(1000000 / phc_rate);
 
 		if (src != CLOCK_INVALID) {
-			if (!read_phc(src, dst, rdelay, phc_readings, &phc_offset, &phc_ts))
+			if (!read_phc(src, dst, phc_readings, &phc_offset, &phc_ts))
 				continue;
 			printf("phc %9lld ", phc_offset);
 		}