diff --git a/apps/emqx_auth/src/emqx_authn/emqx_authn_password_hashing.erl b/apps/emqx_auth/src/emqx_authn/emqx_authn_password_hashing.erl
index 46b44512f..4d74ff48c 100644
--- a/apps/emqx_auth/src/emqx_authn/emqx_authn_password_hashing.erl
+++ b/apps/emqx_auth/src/emqx_authn/emqx_authn_password_hashing.erl
@@ -142,7 +142,7 @@ salt_position(desc) -> "Salt position for PLAIN, MD5, SHA, SHA256 and SHA512 alg
 salt_position(_) -> undefined.
 
 dk_length(type) ->
-    integer();
+    pos_integer();
 dk_length(required) ->
     false;
 dk_length(desc) ->
diff --git a/apps/emqx_auth/src/emqx_authz/emqx_authz_rule_raw.erl b/apps/emqx_auth/src/emqx_authz/emqx_authz_rule_raw.erl
index 0c56be2d1..0f66b3ade 100644
--- a/apps/emqx_auth/src/emqx_authz/emqx_authz_rule_raw.erl
+++ b/apps/emqx_auth/src/emqx_authz/emqx_authz_rule_raw.erl
@@ -98,7 +98,7 @@ validate_rule_topics(RuleRaw) ->
     throw({missing_topic_or_topics, RuleRaw}).
 
 validate_rule_topic(<<"eq ", TopicRaw/binary>>) ->
-    {eq, validate_rule_topic(TopicRaw)};
+    {eq, TopicRaw};
 validate_rule_topic(TopicRaw) when is_binary(TopicRaw) -> TopicRaw.
 
 validate_rule_permission(<<"allow">>) -> allow;