diff --git a/auth/auth_sqlite.go b/auth/auth_sqlite.go
index 71cd86ed..4b7eb38c 100644
--- a/auth/auth_sqlite.go
+++ b/auth/auth_sqlite.go
@@ -332,7 +332,9 @@ func (a *SQLiteAuth) AllowAccess(username string, topicPattern string, read bool
 // ResetAccess removes an access control list entry for a specific username/topic, or (if topic is
 // empty) for an entire user. The parameter topicPattern may include wildcards (*).
 func (a *SQLiteAuth) ResetAccess(username string, topicPattern string) error {
-	if (!AllowedUsername(username) && username != Everyone) || (!AllowedTopicPattern(topicPattern) && topicPattern != "") {
+	if !AllowedUsername(username) && username != Everyone && username != "" {
+		return ErrInvalidArgument
+	} else if !AllowedTopicPattern(topicPattern) && topicPattern != "" {
 		return ErrInvalidArgument
 	}
 	if username == "" && topicPattern == "" {
diff --git a/server/server_firebase_test.go b/server/server_firebase_test.go
index 203960ea..1fdd8a6e 100644
--- a/server/server_firebase_test.go
+++ b/server/server_firebase_test.go
@@ -15,11 +15,11 @@ type testAuther struct {
 	Allow bool
 }
 
-func (t testAuther) Authenticate(username, password string) (*auth.User, error) {
+func (t testAuther) Authenticate(_, _ string) (*auth.User, error) {
 	return nil, errors.New("not used")
 }
 
-func (t testAuther) Authorize(user *auth.User, topic string, perm auth.Permission) error {
+func (t testAuther) Authorize(_ *auth.User, _ string, _ auth.Permission) error {
 	if t.Allow {
 		return nil
 	}