diff --git a/src/main/scala/app/RepositoryViewerController.scala b/src/main/scala/app/RepositoryViewerController.scala
index 00f6755..74fceae 100644
--- a/src/main/scala/app/RepositoryViewerController.scala
+++ b/src/main/scala/app/RepositoryViewerController.scala
@@ -21,7 +21,7 @@
 
 class RepositoryViewerController extends RepositoryViewerControllerBase
   with RepositoryService with AccountService with ActivityService with IssuesService with WebHookService with CommitsService
-  with ReadableUsersAuthenticator with ReferrerAuthenticator with CollaboratorsAuthenticator
+  with ReadableUsersAuthenticator with ReferrerAuthenticator with CollaboratorsAuthenticator with PullRequestService
 
 
 /**
@@ -29,7 +29,7 @@
  */
 trait RepositoryViewerControllerBase extends ControllerBase {
   self: RepositoryService with AccountService with ActivityService with IssuesService with WebHookService with CommitsService
-    with ReadableUsersAuthenticator with ReferrerAuthenticator with CollaboratorsAuthenticator =>
+    with ReadableUsersAuthenticator with ReferrerAuthenticator with CollaboratorsAuthenticator with PullRequestService =>
 
   ArchiveCommand.registerFormat("zip", new ZipFormat)
   ArchiveCommand.registerFormat("tar.gz", new TgzFormat)
@@ -496,6 +496,9 @@
         //refUpdate.setRefLogMessage("merged", true)
         refUpdate.update()
 
+        // update pull request
+        updatePullRequests(repository.owner, repository.name, branch)
+
         // record activity
         recordPushActivity(repository.owner, repository.name, loginAccount.userName, branch,
           List(new CommitInfo(JGitUtil.getRevCommitFromId(git, commitId))))
diff --git a/src/main/scala/service/PullRequestService.scala b/src/main/scala/service/PullRequestService.scala
index 9a3239b..68121f9 100644
--- a/src/main/scala/service/PullRequestService.scala
+++ b/src/main/scala/service/PullRequestService.scala
@@ -3,6 +3,7 @@
 import model.Profile._
 import profile.simple._
 import model.{PullRequest, Issue}
+import util.JGitUtil
 
 trait PullRequestService { self: IssuesService =>
   import PullRequestService._
@@ -81,6 +82,18 @@
       .map { case (t1, t2) => t1 }
       .list
 
+  /**
+   * Fetch pull request contents into refs/pull/${issueId}/head and update pull request table.
+   */
+  def updatePullRequests(owner: String, repository: String, branch: String)(implicit s: Session): Unit =
+    getPullRequestsByRequest(owner, repository, branch, false).foreach { pullreq =>
+      if(Repositories.filter(_.byRepository(pullreq.userName, pullreq.repositoryName)).exists.run){
+        val (commitIdTo, commitIdFrom) = JGitUtil.updatePullRequest(
+          pullreq.userName, pullreq.repositoryName, pullreq.branch, pullreq.issueId,
+          pullreq.requestUserName, pullreq.requestRepositoryName, pullreq.requestBranch)
+        updateCommitId(pullreq.userName, pullreq.repositoryName, pullreq.issueId, commitIdTo, commitIdFrom)
+      }
+    }
 }
 
 object PullRequestService {
diff --git a/src/main/scala/servlet/GitRepositoryServlet.scala b/src/main/scala/servlet/GitRepositoryServlet.scala
index df55d46..7fde407 100644
--- a/src/main/scala/servlet/GitRepositoryServlet.scala
+++ b/src/main/scala/servlet/GitRepositoryServlet.scala
@@ -174,7 +174,7 @@
               case ReceiveCommand.Type.CREATE |
                    ReceiveCommand.Type.UPDATE |
                    ReceiveCommand.Type.UPDATE_NONFASTFORWARD =>
-                updatePullRequests(branchName)
+                updatePullRequests(owner, repository, branchName)
               case _ =>
             }
           }
@@ -211,26 +211,4 @@
       }
     }
   }
-
-  /**
-   * Fetch pull request contents into refs/pull/${issueId}/head and update pull request table.
-   */
-  private def updatePullRequests(branch: String) =
-    getPullRequestsByRequest(owner, repository, branch, false).foreach { pullreq =>
-      if(getRepository(pullreq.userName, pullreq.repositoryName, baseUrl).isDefined){
-        using(Git.open(Directory.getRepositoryDir(pullreq.userName, pullreq.repositoryName)),
-              Git.open(Directory.getRepositoryDir(pullreq.requestUserName, pullreq.requestRepositoryName))){ (oldGit, newGit) =>
-          oldGit.fetch
-            .setRemote(Directory.getRepositoryDir(owner, repository).toURI.toString)
-            .setRefSpecs(new RefSpec(s"refs/heads/${branch}:refs/pull/${pullreq.issueId}/head").setForceUpdate(true))
-            .call
-
-          val commitIdTo = oldGit.getRepository.resolve(s"refs/pull/${pullreq.issueId}/head").getName
-          val commitIdFrom = JGitUtil.getForkedCommitId(oldGit, newGit,
-            pullreq.userName, pullreq.repositoryName, pullreq.branch,
-            pullreq.requestUserName, pullreq.requestRepositoryName, pullreq.requestBranch)
-          updateCommitId(pullreq.userName, pullreq.repositoryName, pullreq.issueId, commitIdTo, commitIdFrom)
-        }
-      }
-    }
 }
diff --git a/src/main/scala/util/JGitUtil.scala b/src/main/scala/util/JGitUtil.scala
index b5e2e3b..0f76f1e 100644
--- a/src/main/scala/util/JGitUtil.scala
+++ b/src/main/scala/util/JGitUtil.scala
@@ -13,6 +13,7 @@
 import org.eclipse.jgit.treewalk.filter._
 import org.eclipse.jgit.diff.DiffEntry.ChangeType
 import org.eclipse.jgit.errors.{ConfigInvalidException, MissingObjectException}
+import org.eclipse.jgit.transport.RefSpec
 import java.util.Date
 import org.eclipse.jgit.api.errors.{JGitInternalException, InvalidRefNameException, RefAlreadyExistsException, NoHeadException}
 import service.RepositoryService
@@ -675,6 +676,25 @@
     }
 
   /**
+   * Fetch pull request contents into refs/pull/${issueId}/head and return (commitIdTo, commitIdFrom)
+   */
+  def updatePullRequest(userName: String, repositoryName:String, branch: String, issueId: Int,
+                        requestUserName: String, requestRepositoryName: String, requestBranch: String):(String, String) =
+    using(Git.open(Directory.getRepositoryDir(userName, repositoryName)),
+          Git.open(Directory.getRepositoryDir(requestUserName, requestRepositoryName))){ (oldGit, newGit) =>
+      oldGit.fetch
+        .setRemote(Directory.getRepositoryDir(requestUserName, requestRepositoryName).toURI.toString)
+        .setRefSpecs(new RefSpec(s"refs/heads/${requestBranch}:refs/pull/${issueId}/head").setForceUpdate(true))
+        .call
+
+      val commitIdTo = oldGit.getRepository.resolve(s"refs/pull/${issueId}/head").getName
+      val commitIdFrom = getForkedCommitId(oldGit, newGit,
+        userName, repositoryName, branch,
+        requestUserName, requestRepositoryName, requestBranch)
+      (commitIdTo, commitIdFrom)
+    }
+
+  /**
    * Returns the last modified commit of specified path
    * @param git the Git object
    * @param startCommit the search base commit id