diff --git a/apps/emqx_lwm2m/rebar.config b/apps/emqx_lwm2m/rebar.config
index f190fa55e..3cbd76c05 100644
--- a/apps/emqx_lwm2m/rebar.config
+++ b/apps/emqx_lwm2m/rebar.config
@@ -4,7 +4,7 @@
 
 {profiles,
  [{test,
-   [{deps, [{er_coap_client, {git, "https://github.com/emqx/er_coap_client", {tag, "v1.0"}}},
+   [{deps, [{er_coap_client, {git, "https://github.com/emqx/er_coap_client", {tag, "v1.0.4"}}},
             {emqx_ct_helpers, {git, "https://github.com/emqx/emqx-ct-helpers", {tag, "1.2.2"}}},
             {emqtt, {git, "https://github.com/emqx/emqtt", {tag, "1.2.0"}}}
            ]}
diff --git a/rebar.config.erl b/rebar.config.erl
index 6c14b6ae8..ce8933570 100644
--- a/rebar.config.erl
+++ b/rebar.config.erl
@@ -89,7 +89,7 @@ project_app_dirs() ->
 
 plugins(HasElixir) ->
     [ {relup_helper,{git,"https://github.com/emqx/relup_helper", {tag, "2.0.0"}}}
-    , {er_coap_client, {git, "https://github.com/emqx/er_coap_client", {tag, "v1.0"}}}
+    , {er_coap_client, {git, "https://github.com/emqx/er_coap_client", {tag, "v1.0.4"}}}
       %% emqx main project does not require port-compiler
       %% pin at root level for deterministic
     , {pc, {git, "https://github.com/emqx/port_compiler.git", {tag, "v1.11.1"}}}