diff --git a/chrony.texi.in b/chrony.texi.in
index d44399a..50cccfc 100644
--- a/chrony.texi.in
+++ b/chrony.texi.in
@@ -1152,6 +1152,7 @@ the configuration file is ignored.
 * manual directive::            Allow manual entry using chronyc's settime cmd
 * maxchange directive::         Set maximum allowed offset
 * maxclockerror directive::     Set maximum frequency error of local clock
+* maxdistance directive::       Set maximum allowed distance of sources
 * maxsamples directive::        Set maximum number of samples per source
 * maxslewrate directive::       Set maximum slew rate
 * maxupdateskew directive::     Stop bad estimates upsetting machine clock
@@ -2441,6 +2442,23 @@ Typical values for <error-in-ppm> might be 10 for a low quality clock
 to 0.1 for a high quality clock using a temperature compensated
 crystal oscillator.
 @c }}}
+@c {{{ maxdistance
+@node maxdistance directive
+@subsection maxdistance
+The @code{maxdistance} directive sets the maximum allowed root distance of the
+sources to not be rejected by the source selection algorithm.  The distance
+includes the accumulated dispersion, which may be large when the source is no
+longer synchronised, and half of the total round-trip delay to the primary
+source.
+
+By default, the maximum distance is 3 seconds.
+
+The syntax is
+
+@example
+maxdistance <seconds>
+@end example
+@c }}}
 @c {{{ maxsamples
 @node maxsamples directive
 @subsection maxsamples
diff --git a/conf.c b/conf.c
index 0d58b0e..25a5705 100644
--- a/conf.c
+++ b/conf.c
@@ -90,6 +90,7 @@ static double correction_time_ratio = 3.0;
 static double max_clock_error = 1.0; /* in ppm */
 static double max_slew_rate = 1e6 / 12.0; /* in ppm */
 
+static double max_distance = 3.0;
 static double reselect_distance = 1e-4;
 static double stratum_weight = 1e-3;
 static double combine_limit = 3.0;
@@ -477,6 +478,8 @@ CNF_ParseLine(const char *filename, int number, char *line)
     parse_maxchange(p);
   } else if (!strcasecmp(command, "maxclockerror")) {
     parse_double(p, &max_clock_error);
+  } else if (!strcasecmp(command, "maxdistance")) {
+    parse_double(p, &max_distance);
   } else if (!strcasecmp(command, "maxsamples")) {
     parse_int(p, &max_samples);
   } else if (!strcasecmp(command, "maxslewrate")) {
@@ -1524,6 +1527,14 @@ CNF_GetMaxSlewRate(void)
 
 /* ================================================== */
 
+double
+CNF_GetMaxDistance(void)
+{
+  return max_distance;
+}
+
+/* ================================================== */
+
 double
 CNF_GetReselectDistance(void)
 {
diff --git a/conf.h b/conf.h
index d8e7cca..75f2764 100644
--- a/conf.h
+++ b/conf.h
@@ -86,6 +86,7 @@ extern double CNF_GetMaxClockError(void);
 extern double CNF_GetCorrectionTimeRatio(void);
 extern double CNF_GetMaxSlewRate(void);
 
+extern double CNF_GetMaxDistance(void);
 extern double CNF_GetReselectDistance(void);
 extern double CNF_GetStratumWeight(void);
 extern double CNF_GetCombineLimit(void);
diff --git a/sources.c b/sources.c
index 4ddee25..017f3bc 100644
--- a/sources.c
+++ b/sources.c
@@ -70,6 +70,7 @@ typedef enum {
   SRC_OK,               /* OK so far, not a final status! */
   SRC_UNSELECTABLE,     /* Has noselect option set */
   SRC_BAD_STATS,        /* Doesn't have valid stats data */
+  SRC_BAD_DISTANCE,     /* Has root distance longer than allowed maximum */
   SRC_WAITS_STATS,      /* Others have bad stats, selection postponed */
   SRC_STALE,            /* Has older samples than others */
   SRC_FALSETICKER,      /* Doesn't agree with others */
@@ -155,6 +156,7 @@ static int selected_source_index; /* Which source index is currently
 /* Number of updates needed to reset the distant status */
 #define DISTANT_PENALTY 32
 
+static double max_distance;
 static double reselect_distance;
 static double stratum_weight;
 static double combine_limit;
@@ -179,6 +181,7 @@ void SRC_Initialise(void) {
   n_sources = 0;
   max_n_sources = 0;
   selected_source_index = INVALID_SOURCE;
+  max_distance = CNF_GetMaxDistance();
   reselect_distance = CNF_GetReselectDistance();
   stratum_weight = CNF_GetStratumWeight();
   combine_limit = CNF_GetCombineLimit();
@@ -653,6 +656,12 @@ SRC_SelectSource(SRC_Instance updated_inst)
       continue;
     }
 
+    /* Require the root distance to be below the allowed maximum */
+    if (si->root_distance > max_distance) {
+      sources[i]->status = SRC_BAD_DISTANCE;
+      continue;
+    }
+
     sources[i]->status = SRC_OK; /* For now */
 
     if (sources[i]->reachability && max_reach_sample_ago < first_sample_ago)
@@ -1216,6 +1225,7 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
     switch (src->status) {
       case SRC_UNSELECTABLE:
       case SRC_BAD_STATS:
+      case SRC_BAD_DISTANCE:
       case SRC_STALE:
       case SRC_WAITS_STATS:
         report->state = RPT_UNREACH;
diff --git a/test/simulation/114-presend b/test/simulation/114-presend
index e9fe66e..8872525 100755
--- a/test/simulation/114-presend
+++ b/test/simulation/114-presend
@@ -6,6 +6,7 @@ test_start "presend option"
 min_sync_time=140
 max_sync_time=260
 client_server_options="presend 6 maxdelay 16"
+client_conf="maxdistance 10"
 
 run_test || test_fail
 check_chronyd_exit || test_fail