diff --git a/include/maxscale/monitor.h b/include/maxscale/monitor.h
index cbaf45917..37b507769 100644
--- a/include/maxscale/monitor.h
+++ b/include/maxscale/monitor.h
@@ -206,7 +206,7 @@ struct monitor
 extern MONITOR *monitor_alloc(char *, char *);
 extern void monitor_free(MONITOR *);
 extern MONITOR *monitor_find(const char *);
-extern void monitorAddServer(MONITOR *mon, SERVER *server);
+extern bool monitorAddServer(MONITOR *mon, SERVER *server);
 extern void monitorRemoveServer(MONITOR *mon, SERVER *server);
 extern void monitorAddUser(MONITOR *, char *, char *);
 extern void monitorAddParameters(MONITOR *monitor, CONFIG_PARAMETER *params);
diff --git a/include/maxscale/service.h b/include/maxscale/service.h
index 37670a5ad..d10c8f0f3 100644
--- a/include/maxscale/service.h
+++ b/include/maxscale/service.h
@@ -240,7 +240,7 @@ bool serviceStartListener(SERVICE *service, const char *name);
 SERVICE* service_find(const char *name);
 
 // TODO: Change binlogrouter to use the functions in config_runtime.h
-void serviceAddBackend(SERVICE *service, SERVER *server);
+bool serviceAddBackend(SERVICE *service, SERVER *server);
 
 /**
  * @brief Check if a service uses a server
diff --git a/server/core/config_runtime.c b/server/core/config_runtime.c
index eb3444088..dd045e76a 100644
--- a/server/core/config_runtime.c
+++ b/server/core/config_runtime.c
@@ -29,23 +29,26 @@ bool runtime_link_server(SERVER *server, const char *target)
     SERVICE *service = service_find(target);
     MONITOR *monitor = service ? NULL : monitor_find(target);
 
-    if (service || monitor)
+    if (service)
     {
-        rval = true;
-
-        if (service)
+        if (serviceAddBackend(service, server))
         {
-            serviceAddBackend(service, server);
             service_serialize_servers(service);
+            rval = true;
         }
-        else if (monitor)
+    }
+    else if (monitor)
+    {
+        if (monitorAddServer(monitor, server))
         {
-            monitorAddServer(monitor, server);
             monitor_serialize_servers(monitor);
+            rval = true;
         }
+    }
 
+    if (rval)
+    {
         const char *type = service ? "service" : "monitor";
-
         MXS_NOTICE("Added server '%s' to %s '%s'", server->unique_name, type, target);
     }
 
diff --git a/server/core/monitor.c b/server/core/monitor.c
index 8f52b0525..9f18037be 100644
--- a/server/core/monitor.c
+++ b/server/core/monitor.c
@@ -247,24 +247,17 @@ monitorStopAll()
  * @param mon           The Monitor instance
  * @param server        The Server to add to the monitoring
  */
-void
-monitorAddServer(MONITOR *mon, SERVER *server)
+bool monitorAddServer(MONITOR *mon, SERVER *server)
 {
-    bool new_server = true;
-    spinlock_acquire(&mon->lock);
+    bool rval = false;
 
-    for (MONITOR_SERVERS *db = mon->databases; db; db = db->next)
+    if (monitor_server_in_use(server))
     {
-        if (db->server == server)
-        {
-            new_server = false;
-        }
+        MXS_ERROR("Server '%s' is already monitored.", server->unique_name);
     }
-
-    spinlock_release(&mon->lock);
-
-    if (new_server)
+    else
     {
+        rval = true;
         MONITOR_SERVERS *db = (MONITOR_SERVERS *)MXS_MALLOC(sizeof(MONITOR_SERVERS));
         MXS_ABORT_IF_NULL(db);
 
@@ -307,6 +300,8 @@ monitorAddServer(MONITOR *mon, SERVER *server)
             monitorStart(mon, mon->parameters);
         }
     }
+
+    return rval;
 }
 
 static void monitor_server_free(MONITOR_SERVERS *tofree)
diff --git a/server/core/service.c b/server/core/service.c
index ee43add49..74731edb5 100644
--- a/server/core/service.c
+++ b/server/core/service.c
@@ -768,15 +768,17 @@ static SERVER_REF* server_ref_create(SERVER *server)
  * @param service       The service to add the server to
  * @param server        The server to add
  */
-void
-serviceAddBackend(SERVICE *service, SERVER *server)
+bool serviceAddBackend(SERVICE *service, SERVER *server)
 {
+    bool rval = false;
+
     if (!serviceHasBackend(service, server))
     {
         SERVER_REF *new_ref = server_ref_create(server);
 
         if (new_ref)
         {
+            rval = true;
             spinlock_acquire(&service->spin);
 
             service->n_dbref++;
@@ -816,6 +818,8 @@ serviceAddBackend(SERVICE *service, SERVER *server)
             spinlock_release(&service->spin);
         }
     }
+
+    return rval;
 }
 
 /**
diff --git a/server/modules/routing/debugcli/debugcmd.c b/server/modules/routing/debugcli/debugcmd.c
index 215658151..113e7cbf2 100644
--- a/server/modules/routing/debugcli/debugcmd.c
+++ b/server/modules/routing/debugcli/debugcmd.c
@@ -852,7 +852,8 @@ static void cmd_AddServer(DCB *dcb, SERVER *server, char *v1, char *v2, char *v3
         }
         else
         {
-            dcb_printf(dcb, "No service or monitor with the name '%s'\n", values[i]);
+            dcb_printf(dcb, "Could not add server '%s' to object '%s'. See error log for more details.\n",
+                       server->unique_name, values[i]);
         }
     }
 }