diff --git a/config.c b/config.c
index 1ae564f..c1d5aeb 100644
--- a/config.c
+++ b/config.c
@@ -96,6 +96,7 @@ struct config_item config_tab[] = {
 	GLOB_ITEM_DBL("first_step_threshold", 0.00002, 0.0, DBL_MAX),
 	GLOB_ITEM_INT("logging_level", LOG_INFO, PRINT_LEVEL_MIN, PRINT_LEVEL_MAX),
 	GLOB_ITEM_INT("max_frequency", 900000000, 0, INT_MAX),
+	GLOB_ITEM_INT("ntpshm_segment", 0, INT_MIN, INT_MAX),
 	GLOB_ITEM_DBL("pi_integral_const", 0.0, 0.0, DBL_MAX),
 	GLOB_ITEM_DBL("pi_integral_exponent", 0.4, -DBL_MAX, DBL_MAX),
 	GLOB_ITEM_DBL("pi_integral_norm_max", 0.3, DBL_MIN, 2.0),
@@ -554,12 +555,6 @@ static enum parser_result parse_global_setting(const char *option,
 			return r;
 		cfg->dds.sanity_freq_limit = val;
 
-	} else if (!strcmp(option, "ntpshm_segment")) {
-		r = get_ranged_int(value, &val, INT_MIN, INT_MAX);
-		if (r != PARSED_OK)
-			return r;
-		*cfg->ntpshm_segment = val;
-
 	} else if (!strcmp(option, "ptp_dst_mac")) {
 		if (MAC_LEN != sscanf(value, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
 				      &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]))
diff --git a/config.h b/config.h
index bdfead7..c1ada46 100644
--- a/config.h
+++ b/config.h
@@ -69,8 +69,6 @@ struct config {
 	struct port_defaults pod;
 	enum servo_type clock_servo;
 
-	int *ntpshm_segment;
-
 	unsigned char *ptp_dst_mac;
 	unsigned char *p2p_dst_mac;
 	unsigned char *udp6_scope;
diff --git a/ntpshm.c b/ntpshm.c
index 8b18e2d..3b62a3f 100644
--- a/ntpshm.c
+++ b/ntpshm.c
@@ -22,12 +22,11 @@
 #include <sys/types.h>
 #include <sys/shm.h>
 
+#include "config.h"
 #include "print.h"
 #include "ntpshm.h"
 #include "servo_private.h"
 
-#define NS_PER_SEC 1000000000
-
 /* NTP leap values */
 #define LEAP_NORMAL 0x0
 #define LEAP_INSERT 0x1
@@ -36,9 +35,6 @@
 /* Key of the first SHM segment */
 #define SHMKEY 0x4e545030
 
-/* Number of the SHM segment to be used */
-int ntpshm_segment = 0;
-
 /* Declaration of the SHM segment from ntp (ntpd/refclock_shm.c) */
 struct shmTime {
 	int    mode; /* 0 - if valid set
@@ -134,9 +130,10 @@ static void ntpshm_leap(struct servo *servo, int leap)
 	s->leap = leap;
 }
 
-struct servo *ntpshm_servo_create(void)
+struct servo *ntpshm_servo_create(struct config *cfg)
 {
 	struct ntpshm_servo *s;
+	int ntpshm_segment = config_get_int(cfg, NULL, "ntpshm_segment");
 	int shmid;
 
 	s = calloc(1, sizeof(*s));
diff --git a/ntpshm.h b/ntpshm.h
index ea54a54..80934e0 100644
--- a/ntpshm.h
+++ b/ntpshm.h
@@ -21,11 +21,6 @@
 
 #include "servo.h"
 
-/**
- * The number of the SHM segment that will be used by newly created servo
- */
-extern int ntpshm_segment;
-
-struct servo *ntpshm_servo_create(void);
+struct servo *ntpshm_servo_create(struct config *cfg);
 
 #endif
diff --git a/phc2sys.c b/phc2sys.c
index c2c611b..4088a91 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -1227,6 +1227,7 @@ int main(int argc, char *argv[])
 	int c, domain_number = 0, pps_fd = -1;
 	int r, wait_sync = 0;
 	int print_level = LOG_INFO, use_syslog = 1, verbose = 0;
+	int ntpshm_segment;
 	double phc_rate, tmp;
 	struct node node = {
 		.sanity_freq_limit = 200000000,
@@ -1334,6 +1335,8 @@ int main(int argc, char *argv[])
 		case 'M':
 			if (get_arg_val_i(c, optarg, &ntpshm_segment, INT_MIN, INT_MAX))
 				return -1;
+			if (config_set_int(cfg, "ntpshm_segment", ntpshm_segment))
+				return -1;
 			break;
 		case 'u':
 			if (get_arg_val_ui(c, optarg, &node.stats_max_count,
diff --git a/ptp4l.c b/ptp4l.c
index b74cda6..b9982c8 100644
--- a/ptp4l.c
+++ b/ptp4l.c
@@ -103,8 +103,6 @@ static struct config cfg_settings = {
 	.transport = TRANS_UDP_IPV4,
 	.clock_servo = CLOCK_SERVO_PI,
 
-	.ntpshm_segment = &ntpshm_segment,
-
 	.ptp_dst_mac = ptp_dst_mac,
 	.p2p_dst_mac = p2p_dst_mac,
 	.udp6_scope = &udp6_scope,
diff --git a/servo.c b/servo.c
index 0449223..9aab7f2 100644
--- a/servo.c
+++ b/servo.c
@@ -43,7 +43,7 @@ struct servo *servo_create(struct config *cfg, enum servo_type type,
 		servo = linreg_servo_create(fadj);
 		break;
 	case CLOCK_SERVO_NTPSHM:
-		servo = ntpshm_servo_create();
+		servo = ntpshm_servo_create(cfg);
 		break;
 	case CLOCK_SERVO_NULLF:
 		servo = nullf_servo_create();