diff --git a/src/main/scala/gitbucket/core/controller/PullRequestsController.scala b/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
index 2ab0e96..2fe7805 100644
--- a/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
+++ b/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
@@ -97,7 +97,9 @@
             diffs,
             isEditable(repository),
             isManageable(repository),
+            hasDeveloperRole(pullreq.requestUserName, pullreq.requestRepositoryName, context.loginAccount),
             repository,
+            getRepository(pullreq.requestUserName, pullreq.requestRepositoryName),
             flash.toMap.map(f => f._1 -> f._2.toString))
         }
       }
@@ -138,19 +140,33 @@
     } getOrElse NotFound()
   })
 
-  get("/:owner/:repository/pull/:id/delete/*")(writableUsersOnly { repository =>
-    params("id").toIntOpt.map { issueId =>
-      val branchName = multiParams("splat").head
-      val userName   = context.loginAccount.get.userName
-      if(repository.repository.defaultBranch != branchName){
-        using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
-          git.branchDelete().setForce(true).setBranchNames(branchName).call()
-          recordDeleteBranchActivity(repository.owner, repository.name, userName, branchName)
+  get("/:owner/:repository/pull/:id/delete_branch")(readableUsersOnly { baseRepository =>
+    (for {
+      issueId <- params("id").toIntOpt
+      loginAccount <- context.loginAccount
+      (issue, pullreq) <- getPullRequest(baseRepository.owner, baseRepository.name, issueId)
+      owner = pullreq.requestUserName
+      name  = pullreq.requestRepositoryName
+      if hasDeveloperRole(owner, name, context.loginAccount)
+    } yield {
+      val repository = getRepository(owner, name).get
+      val branchProtection = getProtectedBranchInfo(owner, name, pullreq.requestBranch)
+      if(branchProtection.enabled){
+        flash += "error" -> s"branch ${pullreq.requestBranch} is protected."
+      } else {
+        if(repository.repository.defaultBranch != pullreq.requestBranch){
+          val userName = context.loginAccount.get.userName
+          using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
+            git.branchDelete().setForce(true).setBranchNames(pullreq.requestBranch).call()
+            recordDeleteBranchActivity(repository.owner, repository.name, userName, pullreq.requestBranch)
+          }
+          createComment(baseRepository.owner, baseRepository.name, userName, issueId, pullreq.requestBranch, "delete_branch")
+        } else {
+          flash += "error" -> s"""Can't delete the default branch "${pullreq.requestBranch}"."""
         }
       }
-      createComment(repository.owner, repository.name, userName, issueId, branchName, "delete_branch")
-      redirect(s"/${repository.owner}/${repository.name}/pull/${issueId}")
-    } getOrElse NotFound()
+      redirect(s"/${baseRepository.owner}/${baseRepository.name}/pull/${issueId}")
+    }) getOrElse NotFound()
   })
 
   post("/:owner/:repository/pull/:id/update_branch")(readableUsersOnly { baseRepository =>
diff --git a/src/main/twirl/gitbucket/core/pulls/conversation.scala.html b/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
index 1785c89..f29d9de 100644
--- a/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
+++ b/src/main/twirl/gitbucket/core/pulls/conversation.scala.html
@@ -7,7 +7,9 @@
   labels: List[gitbucket.core.model.Label],
   isEditable: Boolean,
   isManageable: Boolean,
-  repository: gitbucket.core.service.RepositoryService.RepositoryInfo)(implicit context: gitbucket.core.controller.Context)
+  isManageableForkedRepository: Boolean,
+  repository: gitbucket.core.service.RepositoryService.RepositoryInfo,
+  forkedRepository: Option[gitbucket.core.service.RepositoryService.RepositoryInfo])(implicit context: gitbucket.core.controller.Context)
 @import gitbucket.core.view.helpers
 <div class="col-md-9">
   <div id="comment-list">
@@ -26,11 +28,11 @@
         </div>
       </div>
     }
-    @if(isManageable && issue.closed && pullreq.userName == pullreq.requestUserName && merged &&
-      pullreq.repositoryName == pullreq.requestRepositoryName && repository.branchList.contains(pullreq.requestBranch)){
+    @if(isManageableForkedRepository && issue.closed && merged &&
+      forkedRepository.map(r => (r.branchList.contains(pullreq.requestBranch) && r.repository.defaultBranch != pullreq.requestBranch)).getOrElse(false)){
       <div class="issue-comment-box" style="background-color: #d0eeff;">
         <div class="box-content"class="issue-content" style="border: 1px solid #87a8c9; padding: 10px;">
-          <a href="@helpers.url(repository)/pull/@issue.issueId/delete/@helpers.encodeRefName(pullreq.requestBranch)" class="btn btn-info pull-right delete-branch" data-name="@pullreq.requestBranch">Delete branch</a>
+          <a href="@helpers.url(repository)/pull/@issue.issueId/delete_branch" class="btn btn-info pull-right delete-branch" data-name="@pullreq.requestBranch">Delete branch</a>
           <div>
             <span class="strong">Pull request successfully merged and closed</span>
           </div>
@@ -56,11 +58,9 @@
     $.get('@helpers.url(repository)/pull/@issue.issueId/mergeguide', function(data){ $('.check-conflict').html(data); });
   }
 
-  @if(isManageable){
-    $('.delete-branch').click(function(e){
-      var branchName = $(e.target).data('name');
-      return confirm('Are you sure you want to remove the ' + branchName + ' branch?');
-    });
-  }
+  $('.delete-branch').click(function(e){
+    var branchName = $(e.target).data('name');
+    return confirm('Are you sure you want to remove the ' + branchName + ' branch?');
+  });
 });
 </script>
diff --git a/src/main/twirl/gitbucket/core/pulls/pullreq.scala.html b/src/main/twirl/gitbucket/core/pulls/pullreq.scala.html
index e605677..0606d3e 100644
--- a/src/main/twirl/gitbucket/core/pulls/pullreq.scala.html
+++ b/src/main/twirl/gitbucket/core/pulls/pullreq.scala.html
@@ -9,7 +9,9 @@
   diffs: Seq[gitbucket.core.util.JGitUtil.DiffInfo],
   isEditable: Boolean,
   isManageable: Boolean,
+  isManageableForkedRepository: Boolean,
   repository: gitbucket.core.service.RepositoryService.RepositoryInfo,
+  forkedRepository: Option[gitbucket.core.service.RepositoryService.RepositoryInfo],
   flash: Map[String, String])(implicit context: gitbucket.core.controller.Context)
 @import gitbucket.core.view.helpers
 @import gitbucket.core.model.IssueComment
@@ -83,7 +85,7 @@
           @flash.get("info").map{ info =>
             <div class="alert alert-info">@info</div>
           }
-          @gitbucket.core.pulls.html.conversation(issue, pullreq, comments, issueLabels, collaborators, milestones, labels, isEditable, isManageable, repository)
+          @gitbucket.core.pulls.html.conversation(issue, pullreq, comments, issueLabels, collaborators, milestones, labels, isEditable, isManageable, isManageableForkedRepository, repository, forkedRepository)
         </div>
         <div class="tab-pane" id="commits">
           @gitbucket.core.pulls.html.commits(dayByDayCommits, Some(comments), repository)