diff --git a/apps/emqx_authz/etc/acl.conf b/apps/emqx_authz/etc/acl.conf
index a64287a4a..9964dc7ba 100644
--- a/apps/emqx_authz/etc/acl.conf
+++ b/apps/emqx_authz/etc/acl.conf
@@ -1,15 +1,15 @@
 %%--------------------------------------------------------------------
 %% -type(ipaddr() :: {ipaddr, string()}).
 %%
-%% -type(ipaddrs() :: {ipaddrs, string()}).
+%% -type(ipaddrs() :: {ipaddrs, [string()]}).
 %%
 %% -type(username() :: {user | username, string()} | {user | username, {re, regex()}}).
 %%
 %% -type(clientid() :: {client | clientid, string()} | {client | clientid, {re, regex()}}).
 %%
-%% -type(who() :: ipaddr() | ipaddrs() |username() | clientid() |
-%%                {'and', [ipaddr() | ipaddrs()| username() | clientid()]} |
-%%                {'or',  [ipaddr() | ipaddrs()| username() | clientid()]} |
+%% -type(who() :: ipaddr() | ipaddrs() | username() | clientid() |
+%%                {'and', [ipaddr() | ipaddrs() | username() | clientid()]} |
+%%                {'or',  [ipaddr() | ipaddrs() | username() | clientid()]} |
 %%                all).
 %%
 %% -type(action() :: subscribe | publish | all).