diff --git a/server/modules/monitor/mariadbmon/mariadbserver.cc b/server/modules/monitor/mariadbmon/mariadbserver.cc
index 74a7dfd51..64616a7b8 100644
--- a/server/modules/monitor/mariadbmon/mariadbserver.cc
+++ b/server/modules/monitor/mariadbmon/mariadbserver.cc
@@ -1936,11 +1936,6 @@ bool MariaDBServer::merge_slave_conns(ClusterOperation& op, const SlaveStatusArr
         SlaveStatus slave_conn = conns_to_merge[i];
         string ignore_reason;
         if (conn_can_be_merged(slave_conn, &ignore_reason))
-        {
-            MXS_WARNING("%s was ignored when promoting %s because %s",
-                        slave_conn.to_short_string().c_str(), name(), ignore_reason.c_str());
-        }
-        else
         {
             if (check_modify_conn_name(&slave_conn))
             {
@@ -1958,6 +1953,12 @@ bool MariaDBServer::merge_slave_conns(ClusterOperation& op, const SlaveStatusArr
                 error = true;
             }
         }
+        else
+        {
+            mxb_assert(!ignore_reason.empty());
+            MXS_WARNING("%s was ignored when promoting %s because %s",
+                        slave_conn.to_short_string().c_str(), name(), ignore_reason.c_str());
+        }
     }
 
     return !error;