diff --git a/src/core/ddsi/include/dds/ddsi/q_config.h b/src/core/ddsi/include/dds/ddsi/q_config.h
index b0e160c..d7cd25d 100644
--- a/src/core/ddsi/include/dds/ddsi/q_config.h
+++ b/src/core/ddsi/include/dds/ddsi/q_config.h
@@ -239,6 +239,7 @@ struct config
   int tracingTimestamps;
   int tracingAppendToFile;
   uint32_t allowMulticast;
+  int prefer_multicast;
   enum transport_selector transport_selector;
   enum boolean_default compat_use_ipv6;
   enum boolean_default compat_tcp_enable;
diff --git a/src/core/ddsi/src/q_config.c b/src/core/ddsi/src/q_config.c
index cde5e86..382d2c1 100644
--- a/src/core/ddsi/src/q_config.c
+++ b/src/core/ddsi/src/q_config.c
@@ -244,6 +244,8 @@ static const struct cfgelem general_cfgelems[] = {
 <li><i>ssm</i>: enables the use of SSM (source-specific multicast) for all non-SPDP traffic (if supported)</li>\n\
 </ul>\n\
 <p>When set to \"false\" all multicasting is disabled. The default, \"true\" enables full use of multicasts. Listening for multicasts can be controlled by General/MulticastRecvNetworkInterfaceAddresses.</p>") },
+  { LEAF("PreferMulticast"), 1, "false", ABSOFF(prefer_multicast), 0, uf_boolean, 0, pf_boolean,
+    BLURB("<p>When false (default) Cyclone DDS uses unicast for data whenever there a single unicast suffices. Setting this to true makes it prefer multicasting data, falling back to unicast only when no multicast address is available.</p>") },
   { LEAF("MulticastTimeToLive"), 1, "32", ABSOFF(multicast_ttl), 0, uf_natint_255, 0, pf_int,
     BLURB("<p>This element specifies the time-to-live setting for outgoing multicast packets.</p>") },
   { LEAF("DontRoute"), 1, "false", ABSOFF(dontRoute), 0, uf_boolean, 0, pf_boolean,
diff --git a/src/core/ddsi/src/q_entity.c b/src/core/ddsi/src/q_entity.c
index 53c0bc6..f7d3480 100644
--- a/src/core/ddsi/src/q_entity.c
+++ b/src/core/ddsi/src/q_entity.c
@@ -1107,7 +1107,7 @@ static void rebuild_trace_covered(int nreaders, int nlocs, const nn_locator_t *l
   {
     char buf[DDSI_LOCATORSTRLEN];
     ddsi_locator_to_string(buf, sizeof(buf), &locs[i]);
-    DDS_LOG(DDS_LC_DISCOVERY, "  loc %2d = %-20s %2d {", i, buf, locs_nrds[i]);
+    DDS_LOG(DDS_LC_DISCOVERY, "  loc %2d = %-30s %2d {", i, buf, locs_nrds[i]);
     for (j = 0; j < nreaders; j++)
       if (covered[j * nlocs + i] >= 0)
         DDS_LOG(DDS_LC_DISCOVERY, " %d", covered[j * nlocs + i]);
@@ -1123,7 +1123,9 @@ static int rebuild_select(int nlocs, const nn_locator_t *locs, const int *locs_n
   if (nlocs == 0)
     return -1;
   for (j = 0, i = 1; i < nlocs; i++) {
-    if (locs_nrds[i] > locs_nrds[j])
+    if (config.prefer_multicast && locs_nrds[i] > 0 && ddsi_is_mcaddr(&locs[i]) && !ddsi_is_mcaddr(&locs[j]))
+      j = i; /* obviously first step must be to try and avoid unicast if configuration says so */
+    else if (locs_nrds[i] > locs_nrds[j])
       j = i; /* better coverage */
     else if (locs_nrds[i] == locs_nrds[j])
     {