diff --git a/src/main/scala/service/WikiService.scala b/src/main/scala/service/WikiService.scala
index 9878348..3d09bc3 100644
--- a/src/main/scala/service/WikiService.scala
+++ b/src/main/scala/service/WikiService.scala
@@ -99,40 +99,45 @@
   def revertWikiPage(owner: String, repository: String, from: String, to: String,
                      committer: model.Account, pageName: Option[String]): Boolean = {
     LockUtil.lock(s"${owner}/${repository}/wiki"){
-      using(Git.open(Directory.getWikiWorkDir(owner, repository))){ git =>
-        val reader = git.getRepository.newObjectReader
-        val oldTreeIter = new CanonicalTreeParser
-        oldTreeIter.reset(reader, git.getRepository.resolve(from + "^{tree}"))
+      defining(Directory.getWikiWorkDir(owner, repository)){ workDir =>
+        // clone working copy
+        cloneOrPullWorkingCopy(workDir, owner, repository)
 
-        val newTreeIter = new CanonicalTreeParser
-        newTreeIter.reset(reader, git.getRepository.resolve(to + "^{tree}"))
+        using(Git.open(workDir)){ git =>
+          val reader = git.getRepository.newObjectReader
+          val oldTreeIter = new CanonicalTreeParser
+          oldTreeIter.reset(reader, git.getRepository.resolve(from + "^{tree}"))
 
-        import scala.collection.JavaConverters._
-        val diffs = git.diff.setNewTree(oldTreeIter).setOldTree(newTreeIter).call.asScala.filter { diff =>
-          pageName match {
-            case Some(x) => diff.getNewPath == x + ".md"
-            case None    => true
+          val newTreeIter = new CanonicalTreeParser
+          newTreeIter.reset(reader, git.getRepository.resolve(to + "^{tree}"))
+
+          import scala.collection.JavaConverters._
+          val diffs = git.diff.setNewTree(oldTreeIter).setOldTree(newTreeIter).call.asScala.filter { diff =>
+            pageName match {
+              case Some(x) => diff.getNewPath == x + ".md"
+              case None    => true
+            }
           }
-        }
 
-        val patch = using(new java.io.ByteArrayOutputStream()){ out =>
-          val formatter = new DiffFormatter(out)
-          formatter.setRepository(git.getRepository)
-          formatter.format(diffs.asJava)
-          new String(out.toByteArray, "UTF-8")
-        }
+          val patch = using(new java.io.ByteArrayOutputStream()){ out =>
+            val formatter = new DiffFormatter(out)
+            formatter.setRepository(git.getRepository)
+            formatter.format(diffs.asJava)
+            new String(out.toByteArray, "UTF-8")
+          }
 
-        try {
-          git.apply.setPatch(new java.io.ByteArrayInputStream(patch.getBytes("UTF-8"))).call
-          git.add.addFilepattern(".").call
-          git.commit.setCommitter(committer.userName, committer.mailAddress).setMessage(pageName match {
-            case Some(x) => s"Revert ${from} ... ${to} on ${x}"
-            case None    => s"Revert ${from} ... ${to}"
-          }).call
-          git.push.call
-          true
-        } catch {
-          case ex: PatchApplyException => false
+          try {
+            git.apply.setPatch(new java.io.ByteArrayInputStream(patch.getBytes("UTF-8"))).call
+            git.add.addFilepattern(".").call
+            git.commit.setCommitter(committer.userName, committer.mailAddress).setMessage(pageName match {
+              case Some(x) => s"Revert ${from} ... ${to} on ${x}"
+              case None    => s"Revert ${from} ... ${to}"
+            }).call
+            git.push.call
+            true
+          } catch {
+            case ex: PatchApplyException => false
+          }
         }
       }
     }