diff --git a/pkg/models/team_members.go b/pkg/models/team_members.go
index 2899ed5ac..10231d111 100644
--- a/pkg/models/team_members.go
+++ b/pkg/models/team_members.go
@@ -110,18 +110,13 @@ func (tm *TeamMember) Delete(s *xorm.Session, _ web.Auth) (err error) {
 }
 
 func (tm *TeamMember) CheckMembership(s *xorm.Session) (exists bool, err error) {
-	member, err := user2.GetUserByUsername(s, tm.Username)
-	if err != nil {
-		return
-	}
-	tm.UserID = member.ID
 	exists, err = s.
 		Where("team_id = ? AND user_id = ?", tm.TeamID, tm.UserID).
 		Get(&TeamMember{})
-	if exists {
+	if exists && err == nil {
 		return
 	}
-	return exists, ErrUserIsMemberOfTeam{tm.UserID, tm.UserID}
+	return exists, err
 }
 
 // Update toggles a team member's admin status