diff --git a/rel/reltool.config b/rel/reltool.config
index 411543559..c79fa74cd 100644
--- a/rel/reltool.config
+++ b/rel/reltool.config
@@ -10,21 +10,22 @@
          stdlib,
          sasl,
          asn1,
-		 syntax_tools,
-		 ssl,
-		 crypto,
+         syntax_tools,
+         ssl,
+         crypto,
          eldap,
          xmerl,
-		 os_mon,
-		 inets,
-		 goldrush,
+         os_mon,
+         inets,
+         goldrush,
          compiler,
          runtime_tools,
-		 lager,
+         {observer, load},
+         lager,
          gen_logger,
          gproc,
-		 esockd,
-		 mochiweb,
+         esockd,
+         mochiweb,
          emqttd
         ]},
        {rel, "start_clean", "",
@@ -56,6 +57,7 @@
        {app, inets, [{incl_cond, include}]},
        {app, compiler, [{incl_cond, include}]},
        {app, runtime_tools, [{incl_cond, include}]},
+       {app, observer, [{incl_cond, include}]},
        {app, goldrush, [{incl_cond, include}]},
        {app, gen_logger, [{incl_cond, include}]},
        {app, lager, [{incl_cond, include}]},