diff --git a/rel/emqx_vars b/rel/emqx_vars
index cd484a023..9498fa73d 100644
--- a/rel/emqx_vars
+++ b/rel/emqx_vars
@@ -7,11 +7,15 @@ REL_VSN="{{ release_version }}"
 ERTS_VSN="{{ erts_vsn }}"
 ERL_OPTS="{{ erl_opts }}"
 RUNNER_BIN_DIR="{{ runner_bin_dir }}"
-RUNNER_LOG_DIR="{{ runner_log_dir }}"
 RUNNER_LIB_DIR="{{ runner_lib_dir }}"
+IS_ELIXIR="${IS_ELIXIR:-{{ is_elixir }}}"
+
+if [ -z "${RUNNER_LOG_DIR:-}" ]; then
+    RUNNER_LOG_DIR="{{ runner_log_dir }}"
+fi
+
 EMQX_ETC_DIR="{{ emqx_etc_dir }}"
 RUNNER_USER="{{ runner_user }}"
-IS_ELIXIR="${IS_ELIXIR:-{{ is_elixir }}}"
 SCHEMA_MOD="{{ emqx_schema_mod }}"
 IS_ENTERPRISE="{{ is_enterprise }}"