diff --git a/tests/integration/api_comment_attachment_test.go b/tests/integration/api_comment_attachment_test.go
index 9761e06987..7df8ededec 100644
--- a/tests/integration/api_comment_attachment_test.go
+++ b/tests/integration/api_comment_attachment_test.go
@@ -36,6 +36,14 @@ func TestAPIGetCommentAttachment(t *testing.T) {
 	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: comment.Issue.RepoID})
 	repoOwner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
 
+	t.Run("UnrelatedCommentID", func(t *testing.T) {
+		repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 4})
+		repoOwner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+		token := getUserToken(t, repoOwner.Name, auth_model.AccessTokenScopeWriteIssue)
+		req := NewRequestf(t, "GET", "/api/v1/repos/%s/%s/issues/comments/%d/assets/%d?token=%s", repoOwner.Name, repo.Name, comment.ID, attachment.ID, token)
+		MakeRequest(t, req, http.StatusNotFound)
+	})
+
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeReadIssue)
 	req := NewRequestf(t, "GET", "/api/v1/repos/%s/%s/issues/comments/%d/assets/%d?token=%s", repoOwner.Name, repo.Name, comment.ID, attachment.ID, token)