diff --git a/src/main/scala/gitbucket/core/api/CreateAPullRequest.scala b/src/main/scala/gitbucket/core/api/CreateAPullRequest.scala
index e02d065..112e721 100644
--- a/src/main/scala/gitbucket/core/api/CreateAPullRequest.scala
+++ b/src/main/scala/gitbucket/core/api/CreateAPullRequest.scala
@@ -15,3 +15,11 @@
   base: String,
   maintainer_can_modify: Option[Boolean]
 )
+
+case class UpdateAPullRequest(
+  title: Option[String],
+  body: Option[String],
+  state: Option[String],
+  base: Option[String],
+  maintainer_can_modify: Option[Boolean],
+)
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiPullRequestControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiPullRequestControllerBase.scala
index aa5e8da..1774f82 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiPullRequestControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiPullRequestControllerBase.scala
@@ -161,8 +161,28 @@
 
   /*
    * v. Update a pull request
-   * https://developer.github.com/v3/pulls/#update-a-pull-request
+   * https://docs.github.com/en/rest/reference/pulls#update-a-pull-request
    */
+  patch("/api/v3/repos/:owner/:repository/pulls/:id")(referrersOnly { repository =>
+    (for {
+      issueId <- params("id").toIntOpt
+      account <- context.loginAccount
+      settings = context.settings
+      data <- extractFromJsonBody[UpdateAPullRequest]
+    } yield {
+      updatePullRequestsByApi(
+        repository,
+        issueId,
+        account,
+        settings,
+        data.title,
+        data.body,
+        data.state,
+        data.base
+      )
+      JsonFormat(getApiPullRequest(repository, issueId))
+    }) getOrElse NotFound()
+  })
 
   /*
    * vi. List commits on a pull request
diff --git a/src/main/scala/gitbucket/core/service/PullRequestService.scala b/src/main/scala/gitbucket/core/service/PullRequestService.scala
index 8ab531c..0b211a5 100644
--- a/src/main/scala/gitbucket/core/service/PullRequestService.scala
+++ b/src/main/scala/gitbucket/core/service/PullRequestService.scala
@@ -14,7 +14,7 @@
 import gitbucket.core.util.Implicits._
 import gitbucket.core.util.JGitUtil
 import gitbucket.core.util.StringUtil._
-import gitbucket.core.util.JGitUtil.{CommitInfo, DiffInfo}
+import gitbucket.core.util.JGitUtil.{CommitInfo, DiffInfo, getBranches}
 import gitbucket.core.view
 import gitbucket.core.view.helpers
 import org.eclipse.jgit.api.Git
@@ -58,6 +58,15 @@
       .map(pr => pr.isDraft)
       .update(false)
 
+  def updateBaseBranch(owner: String, repository: String, issueId: Int, baseBranch: String, commitIdTo: String)(
+    implicit s: Session
+  ): Unit = {
+    PullRequests
+      .filter(_.byPrimaryKey(owner, repository, issueId))
+      .map(pr => pr.branch -> pr.commitIdTo)
+      .update((baseBranch, commitIdTo))
+  }
+
   def getPullRequestCountGroupByUser(closed: Boolean, owner: Option[String], repository: Option[String])(
     implicit s: Session
   ): List[PullRequestCount] =
@@ -293,6 +302,76 @@
     }
   }
 
+  def updatePullRequestsByApi(
+    repository: RepositoryInfo,
+    issueId: Int,
+    loginAccount: Account,
+    settings: SystemSettings,
+    title: Option[String],
+    body: Option[String],
+    state: Option[String],
+    base: Option[String]
+  )(
+    implicit s: Session,
+    c: JsonFormat.Context
+  ): Unit = {
+    getPullRequest(repository.owner, repository.name, issueId).foreach {
+      case (issue, pr) =>
+        if (Repositories.filter(_.byRepository(pr.userName, pr.repositoryName)).exists.run) {
+          // Update base branch
+          base.foreach { _base =>
+            if (pr.branch != _base) {
+              Using.resource(Git.open(getRepositoryDir(repository.owner, repository.name))) { git =>
+                getBranches(git, repository.repository.defaultBranch, origin = true)
+                  .find(_.name == _base)
+                  .foreach(br => updateBaseBranch(repository.owner, repository.name, issueId, br.name, br.commitId))
+              }
+              createComment(
+                repository.owner,
+                repository.name,
+                loginAccount.userName,
+                issue.issueId,
+                pr.branch + "\r\n" + _base,
+                "change_base_branch"
+              )
+            }
+          }
+          // Update title and content
+          title.foreach { _title =>
+            updateIssue(repository.owner, repository.name, issueId, _title, body)
+            if (issue.title != _title) {
+              createComment(
+                repository.owner,
+                repository.name,
+                loginAccount.userName,
+                issue.issueId,
+                issue.title + "\r\n" + _title,
+                "change_title"
+              )
+            }
+          }
+          // Update state
+          val action = (state, issue.closed) match {
+            case (Some("open"), true) =>
+              updateClosed(repository.owner, repository.name, issueId, closed = false)
+              "reopened"
+            case (Some("closed"), false) =>
+              updateClosed(repository.owner, repository.name, issueId, closed = true)
+              "closed"
+            case _ => "edited"
+          }
+          // Call web hook
+          callPullRequestWebHookByRequestBranch(
+            action,
+            getRepository(repository.owner, repository.name).get,
+            pr.requestBranch,
+            loginAccount,
+            settings
+          )
+        }
+    }
+  }
+
   def getPullRequestByRequestCommit(
     userName: String,
     repositoryName: String,
diff --git a/src/main/twirl/gitbucket/core/issues/commentlist.scala.html b/src/main/twirl/gitbucket/core/issues/commentlist.scala.html
index 7d0397d..a0e36a0 100644
--- a/src/main/twirl/gitbucket/core/issues/commentlist.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/commentlist.scala.html
@@ -243,6 +243,17 @@
           </div>
         </div>
       }
+      case "change_base_branch" => {
+        <div class="discussion-item discussion-item-pencil">
+          <div class="discussion-item-header">
+            <span class="discussion-item-icon"><i class="octicon octicon-pencil"></i></span>
+            @helpers.avatar(comment.commentedUserName, 16)
+            @helpers.user(comment.commentedUserName, styleClass="username strong")
+            change base branch from <code>@convertLineSeparator(comment.content, "LF").split("\n")(0)</code> to <code>@convertLineSeparator(comment.content, "LF").split("\n")(1)</code>
+            @gitbucket.core.helper.html.datetimeago(comment.registeredDate)
+          </div>
+        </div>
+      }
       case _ => {
         @showFormattedComment(comment)
       }