diff --git a/routers/hat/hat.go b/routers/hat/hat.go
index 3e871f8..1ff0d48 100644
--- a/routers/hat/hat.go
+++ b/routers/hat/hat.go
@@ -102,6 +102,7 @@ func Routers(ctx gocontext.Context) *web.Route {
 						m.Get("/files", context.RepoRef(), repo.GetPullFiles)
 						m.Group("/versions", func() {
 							m.Get("", repo.ListPullRequestVersions)
+							m.Get("/{versionId}/diff", context.RepoRef(), repo.GetPullRequestVersionDiff)
 						})
 					})
 				}, mustAllowPulls, reqRepoReader(unit_model.TypeCode), context.ReferencesGitRepo())
diff --git a/routers/hat/repo/pull_version.go b/routers/hat/repo/pull_version.go
index d4eaea9..0527273 100644
--- a/routers/hat/repo/pull_version.go
+++ b/routers/hat/repo/pull_version.go
@@ -18,7 +18,7 @@ import (
 )
 
 func ListPullRequestVersions(ctx *context.APIContext) {
-	pr, err := issues_model.GetPullRequestByIndex(ctx, ctx.Repo.Repository.RepoID, ctx.ParamsInt64(":index"))
+	pr, err := issues_model.GetPullRequestByIndex(ctx, ctx.Repo.Repository.ID, ctx.ParamsInt64(":index"))
 	if err != nil {
 		if issues_model.IsErrPullRequestNotExist(err) {
 			ctx.NotFound()
@@ -89,7 +89,7 @@ func GetPullRequestVersionDiff(ctx *context.APIContext) {
 	if filepath == "" {
 		ctx.JSON(http.StatusOK, diffs)
 	} else {
-		var targetDiffFile *hat_gitdiff.DiffFile
+		targetDiffFile := &hat_gitdiff.DiffFile{}
 		for _, file := range diffs.Files {
 			if file.Name == filepath {
 				if diffString, err := hat_git.GetDiffStringByFilePath(ctx.Repo.GitRepo, prv.BaseCommitID, prv.HeadCommitID, file.Name); err == nil {
@@ -117,9 +117,6 @@ func GetPullRequestVersionDiff(ctx *context.APIContext) {
 					}
 					targetDiffFile.Diff = strings.Join(afterStrings, "\n")
 				}
-				targetDiffFile = &hat_gitdiff.DiffFile{
-					DiffFile: *file,
-				}
 				break
 			}
 		}