diff --git a/routers/api/v1/repo/issue_reaction.go b/routers/api/v1/repo/issue_reaction.go
index b87d636b80..12614467bb 100644
--- a/routers/api/v1/repo/issue_reaction.go
+++ b/routers/api/v1/repo/issue_reaction.go
@@ -61,6 +61,12 @@ func GetIssueCommentReactions(ctx *context.APIContext) {
 
 	if err := comment.LoadIssue(ctx); err != nil {
 		ctx.Error(http.StatusInternalServerError, "comment.LoadIssue", err)
+		return
+	}
+
+	if comment.Issue.RepoID != ctx.Repo.Repository.ID {
+		ctx.NotFound()
+		return
 	}
 
 	if !ctx.Repo.CanReadIssuesOrPulls(comment.Issue.IsPull) {