diff --git a/candm.h b/candm.h
index 0894ad5..b4e41f1 100644
--- a/candm.h
+++ b/candm.h
@@ -111,7 +111,8 @@
 #define REQ_DOFFSET2 71
 #define REQ_MODIFY_SELECTOPTS 72
 #define REQ_MODIFY_OFFSET 73
-#define N_REQUEST_TYPES 74
+#define REQ_LOCAL3 74
+#define N_REQUEST_TYPES 75
 
 /* Structure used to exchange timespecs independent of time_t size */
 typedef struct {
@@ -237,6 +238,7 @@ typedef struct {
   int32_t stratum;
   Float distance;
   int32_t orphan;
+  Float activate;
   int32_t EOR;
 } REQ_Local;
 
diff --git a/client.c b/client.c
index 0231b9e..a1e213f 100644
--- a/client.c
+++ b/client.c
@@ -755,22 +755,23 @@ static int
 process_cmd_local(CMD_Request *msg, char *line)
 {
   int on_off, stratum = 0, orphan = 0;
-  double distance = 0.0;
+  double distance = 0.0, activate = 0.0;
 
   if (!strcmp(line, "off")) {
     on_off = 0;
-  } else if (CPS_ParseLocal(line, &stratum, &orphan, &distance)) {
+  } else if (CPS_ParseLocal(line, &stratum, &orphan, &distance, &activate)) {
     on_off = 1;
   } else {
     LOG(LOGS_ERR, "Invalid syntax for local command");
     return 0;
   }
 
-  msg->command = htons(REQ_LOCAL2);
+  msg->command = htons(REQ_LOCAL3);
   msg->data.local.on_off = htonl(on_off);
   msg->data.local.stratum = htonl(stratum);
   msg->data.local.distance = UTI_FloatHostToNetwork(distance);
   msg->data.local.orphan = htonl(orphan);
+  msg->data.local.activate = UTI_FloatHostToNetwork(activate);
 
   return 1;
 }
diff --git a/cmdmon.c b/cmdmon.c
index b2cdc14..49583b8 100644
--- a/cmdmon.c
+++ b/cmdmon.c
@@ -146,6 +146,7 @@ static const char permissions[] = {
   PERMIT_AUTH, /* DOFFSET2 */
   PERMIT_AUTH, /* MODIFY_SELECTOPTS */
   PERMIT_AUTH, /* MODIFY_OFFSET */
+  PERMIT_AUTH, /* LOCAL3 */
 };
 
 /* ================================================== */
@@ -531,7 +532,8 @@ handle_local(CMD_Request *rx_message, CMD_Reply *tx_message)
   if (ntohl(rx_message->data.local.on_off)) {
     REF_EnableLocal(ntohl(rx_message->data.local.stratum),
                     UTI_FloatNetworkToHost(rx_message->data.local.distance),
-                    ntohl(rx_message->data.local.orphan));
+                    ntohl(rx_message->data.local.orphan),
+                    UTI_FloatNetworkToHost(rx_message->data.local.activate));
   } else {
     REF_DisableLocal();
   }
@@ -1649,8 +1651,8 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
         case REQ_SETTIME:
           handle_settime(&rx_message, &tx_message);
           break;
-        
-        case REQ_LOCAL2:
+
+        case REQ_LOCAL3:
           handle_local(&rx_message, &tx_message);
           break;
 
diff --git a/cmdparse.c b/cmdparse.c
index 0a80fc0..77447dc 100644
--- a/cmdparse.c
+++ b/cmdparse.c
@@ -296,13 +296,14 @@ CPS_ParseAllowDeny(char *line, int *all, IPAddr *ip, int *subnet_bits)
 /* ================================================== */
 
 int
-CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance)
+CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance, double *activate)
 {
   int n;
   char *cmd;
 
   *stratum = 10;
   *distance = 1.0;
+  *activate = 0.0;
   *orphan = 0;
 
   while (*line) {
@@ -319,6 +320,9 @@ CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance)
     } else if (!strcasecmp(cmd, "distance")) {
       if (sscanf(line, "%lf%n", distance, &n) != 1)
         return 0;
+    } else if (!strcasecmp(cmd, "activate")) {
+      if (sscanf(line, "%lf%n", activate, &n) != 1)
+        return 0;
     } else {
       return 0;
     }
diff --git a/cmdparse.h b/cmdparse.h
index 095a8e2..f0bc7a4 100644
--- a/cmdparse.h
+++ b/cmdparse.h
@@ -47,7 +47,7 @@ extern int CPS_GetSelectOption(char *option);
 extern int CPS_ParseAllowDeny(char *line, int *all, IPAddr *ip, int *subnet_bits);
 
 /* Parse a command to enable local reference */
-extern int CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance);
+extern int CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance, double *activate);
 
 /* Remove extra white-space and comments */
 extern void CPS_NormalizeLine(char *line);
diff --git a/conf.c b/conf.c
index 7426e61..01ace0d 100644
--- a/conf.c
+++ b/conf.c
@@ -129,6 +129,7 @@ static int enable_local=0;
 static int local_stratum;
 static int local_orphan;
 static double local_distance;
+static double local_activate;
 
 /* Threshold (in seconds) - if absolute value of initial error is less
    than this, slew instead of stepping */
@@ -1069,7 +1070,7 @@ parse_log(char *line)
 static void
 parse_local(char *line)
 {
-  if (!CPS_ParseLocal(line, &local_stratum, &local_orphan, &local_distance))
+  if (!CPS_ParseLocal(line, &local_stratum, &local_orphan, &local_distance, &local_activate))
     command_parse_error();
   enable_local = 1;
 }
@@ -2169,12 +2170,13 @@ CNF_GetCommandPort(void) {
 /* ================================================== */
 
 int
-CNF_AllowLocalReference(int *stratum, int *orphan, double *distance)
+CNF_AllowLocalReference(int *stratum, int *orphan, double *distance, double *activate)
 {
   if (enable_local) {
     *stratum = local_stratum;
     *orphan = local_orphan;
     *distance = local_distance;
+    *activate = local_activate;
     return 1;
   } else {
     return 0;
diff --git a/conf.h b/conf.h
index 4479c9c..fb45fb7 100644
--- a/conf.h
+++ b/conf.h
@@ -108,7 +108,7 @@ extern double CNF_GetReselectDistance(void);
 extern double CNF_GetStratumWeight(void);
 extern double CNF_GetCombineLimit(void);
 
-extern int CNF_AllowLocalReference(int *stratum, int *orphan, double *distance);
+extern int CNF_AllowLocalReference(int *stratum, int *orphan, double *distance, double *activate);
 
 extern void CNF_SetupAccessRestrictions(void);
 
diff --git a/doc/chrony.conf.adoc b/doc/chrony.conf.adoc
index b6cd421..88d46c9 100644
--- a/doc/chrony.conf.adoc
+++ b/doc/chrony.conf.adoc
@@ -1675,6 +1675,14 @@ The current root distance can be calculated from root delay and root dispersion
 ----
 distance = delay / 2 + dispersion
 ----
+*activate* _distance_:::
+This option sets an activating root distance for the local reference. The
+local reference will not be used until the root distance drops below the
+configured value for the first time. This can be used to prevent the local
+reference from being activated on a server which has never been synchronised
+with an upstream server. The default value of 0.0 causes no activating
+distance to be used, such that the local reference is always eligible for
+activation.
 *orphan*:::
 This option enables a special '`orphan`' mode, where sources with stratum equal
 to the local _stratum_ are assumed to not serve real time. They are ignored
@@ -1697,7 +1705,7 @@ The *orphan* mode is compatible with the *ntpd*'s orphan mode (enabled by the
 An example of the directive is:
 +
 ----
-local stratum 10 orphan distance 0.1
+local stratum 10 orphan distance 0.1 activate 0.5
 ----
 
 [[ntpsigndsocket]]*ntpsigndsocket* _directory_::
diff --git a/pktlength.c b/pktlength.c
index 3cca306..8d5ffa7 100644
--- a/pktlength.c
+++ b/pktlength.c
@@ -111,7 +111,7 @@ static const struct request_length request_lengths[] = {
   REQ_LENGTH_ENTRY(null, null),                 /* REFRESH */
   REQ_LENGTH_ENTRY(null, server_stats),         /* SERVER_STATS */
   { 0, 0 },                                     /* CLIENT_ACCESSES_BY_INDEX2 - not supported */
-  REQ_LENGTH_ENTRY(local, null),                /* LOCAL2 */
+  { 0, 0 },                                     /* LOCAL2 - not supported */
   REQ_LENGTH_ENTRY(ntp_data, ntp_data),         /* NTP_DATA */
   { 0, 0 },                                     /* ADD_SERVER2 */
   { 0, 0 },                                     /* ADD_PEER2 */
@@ -131,6 +131,7 @@ static const struct request_length request_lengths[] = {
   REQ_LENGTH_ENTRY(doffset, null),              /* DOFFSET2 */
   REQ_LENGTH_ENTRY(modify_select_opts, null),   /* MODIFY_SELECTOPTS */
   REQ_LENGTH_ENTRY(modify_offset, null),        /* MODIFY_OFFSET */
+  REQ_LENGTH_ENTRY(local, null),                /* LOCAL3 */
 };
 
 static const uint16_t reply_lengths[] = {
diff --git a/reference.c b/reference.c
index 1ac6cb9..ffe290c 100644
--- a/reference.c
+++ b/reference.c
@@ -54,6 +54,8 @@ static int enable_local_stratum;
 static int local_stratum;
 static int local_orphan;
 static double local_distance;
+static int local_activate_ok;
+static double local_activate;
 static struct timespec local_ref_time;
 static NTP_Leap our_leap_status;
 static int our_leap_sec;
@@ -207,6 +209,7 @@ REF_Initialise(void)
   our_frequency_sd = 0.0;
   our_offset_sd = 0.0;
   drift_file_age = 0.0;
+  local_activate_ok = 0;
 
   /* Now see if we can get the drift file opened */
   drift_file = CNF_GetDriftFile();
@@ -245,7 +248,8 @@ REF_Initialise(void)
 
   correction_time_ratio = CNF_GetCorrectionTimeRatio();
 
-  enable_local_stratum = CNF_AllowLocalReference(&local_stratum, &local_orphan, &local_distance);
+  enable_local_stratum = CNF_AllowLocalReference(&local_stratum, &local_orphan,
+                                                 &local_distance, &local_activate);
   UTI_ZeroTimespec(&local_ref_time);
 
   leap_when = 0;
@@ -1132,7 +1136,7 @@ REF_GetReferenceParams
  double *root_dispersion
 )
 {
-  double dispersion, delta;
+  double dispersion, delta, distance;
 
   assert(initialised);
 
@@ -1142,11 +1146,16 @@ REF_GetReferenceParams
     dispersion = 0.0;
   }
 
+  distance = our_root_delay / 2 + dispersion;
+
+  if (local_activate == 0.0 || (are_we_synchronised && distance < local_activate))
+    local_activate_ok = 1;
+
   /* Local reference is active when enabled and the clock is not synchronised
      or the root distance exceeds the threshold */
 
   if (are_we_synchronised &&
-      !(enable_local_stratum && our_root_delay / 2 + dispersion > local_distance)) {
+      !(enable_local_stratum && local_activate_ok && distance > local_distance)) {
 
     *is_synchronised = 1;
 
@@ -1158,7 +1167,7 @@ REF_GetReferenceParams
     *root_delay = our_root_delay;
     *root_dispersion = dispersion;
 
-  } else if (enable_local_stratum) {
+  } else if (enable_local_stratum && local_activate_ok) {
 
     *is_synchronised = 0;
 
@@ -1258,12 +1267,13 @@ REF_ModifyMakestep(int limit, double threshold)
 /* ================================================== */
 
 void
-REF_EnableLocal(int stratum, double distance, int orphan)
+REF_EnableLocal(int stratum, double distance, int orphan, double activate)
 {
   enable_local_stratum = 1;
   local_stratum = CLAMP(1, stratum, NTP_MAX_STRATUM - 1);
   local_distance = distance;
   local_orphan = !!orphan;
+  local_activate = activate;
   LOG(LOGS_INFO, "%s local reference mode", "Enabled");
 }
 
diff --git a/reference.h b/reference.h
index 73454d4..2eddcae 100644
--- a/reference.h
+++ b/reference.h
@@ -185,7 +185,7 @@ extern void REF_ModifyMaxupdateskew(double new_max_update_skew);
 /* Modify makestep settings */
 extern void REF_ModifyMakestep(int limit, double threshold);
 
-extern void REF_EnableLocal(int stratum, double distance, int orphan);
+extern void REF_EnableLocal(int stratum, double distance, int orphan, double activate);
 extern void REF_DisableLocal(void);
 
 /* Check if either of the current raw and cooked time, and optionally a