diff --git a/models/issue.go b/models/issue.go
index 331ea01fd..f115d7621 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -1034,6 +1034,9 @@ func newIssueAttempt(repo *Repository, issue *Issue, labelIDs []int64, uuids []s
 
 // GetIssueByIndex returns raw issue without loading attributes by index in a repository.
 func GetIssueByIndex(repoID, index int64) (*Issue, error) {
+	if index < 1 {
+		return nil, ErrIssueNotExist{}
+	}
 	issue := &Issue{
 		RepoID: repoID,
 		Index:  index,