diff --git a/src/emqx_topic.erl b/src/emqx_topic.erl
index cda057f06..e4ba90023 100644
--- a/src/emqx_topic.erl
+++ b/src/emqx_topic.erl
@@ -42,7 +42,7 @@
 -type(word() :: '' | '+' | '#' | binary()).
 -type(words() :: list(word())).
 
--define(MAX_TOPIC_LEN, 4096).
+-define(MAX_TOPIC_LEN, 65535).
 
 %%--------------------------------------------------------------------
 %% APIs