diff --git a/models/pull.go b/models/pull.go
index b25c52571d7..174faee97ab 100644
--- a/models/pull.go
+++ b/models/pull.go
@@ -152,6 +152,9 @@ func (pr *PullRequest) loadIssue(e Engine) (err error) {
 	}
 
 	pr.Issue, err = getIssueByID(e, pr.IssueID)
+	if err == nil {
+		pr.Issue.PullRequest = pr
+	}
 	return err
 }
 
diff --git a/modules/notification/action/action.go b/modules/notification/action/action.go
index dd4dc0ae323..70ab9975b23 100644
--- a/modules/notification/action/action.go
+++ b/modules/notification/action/action.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification/base"
 )
@@ -191,3 +192,17 @@ func (a *actionNotifier) NotifyPullRequestReview(pr *models.PullRequest, review
 		log.Error("notify watchers '%d/%d': %v", review.Reviewer.ID, review.Issue.RepoID, err)
 	}
 }
+
+func (*actionNotifier) NotifyMergePullRequest(pr *models.PullRequest, doer *models.User, baseRepo *git.Repository) {
+	if err := models.NotifyWatchers(&models.Action{
+		ActUserID: doer.ID,
+		ActUser:   doer,
+		OpType:    models.ActionMergePullRequest,
+		Content:   fmt.Sprintf("%d|%s", pr.Issue.Index, pr.Issue.Title),
+		RepoID:    pr.Issue.Repo.ID,
+		Repo:      pr.Issue.Repo,
+		IsPrivate: pr.Issue.Repo.IsPrivate,
+	}); err != nil {
+		log.Error("NotifyWatchers [%d]: %v", pr.ID, err)
+	}
+}
diff --git a/modules/notification/mail/mail.go b/modules/notification/mail/mail.go
index 24f68bd6428..558c9a6243b 100644
--- a/modules/notification/mail/mail.go
+++ b/modules/notification/mail/mail.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification/base"
 	"code.gitea.io/gitea/services/mailer"
@@ -98,3 +99,14 @@ func (m *mailNotifier) NotifyIssueChangeAssignee(doer *models.User, issue *model
 		mailer.SendIssueAssignedMail(issue, doer, ct, comment, []string{assignee.Email})
 	}
 }
+
+func (m *mailNotifier) NotifyMergePullRequest(pr *models.PullRequest, doer *models.User, baseRepo *git.Repository) {
+	if err := pr.LoadIssue(); err != nil {
+		log.Error("pr.LoadIssue: %v", err)
+		return
+	}
+
+	if err := mailer.MailParticipants(pr.Issue, doer, models.ActionClosePullRequest); err != nil {
+		log.Error("MailParticipants: %v", err)
+	}
+}
diff --git a/modules/notification/webhook/webhook.go b/modules/notification/webhook/webhook.go
index 43be0d2e1cb..213e33c0968 100644
--- a/modules/notification/webhook/webhook.go
+++ b/modules/notification/webhook/webhook.go
@@ -521,6 +521,44 @@ func (m *webhookNotifier) NotifyPushCommits(pusher *models.User, repo *models.Re
 	}
 }
 
+func (*webhookNotifier) NotifyMergePullRequest(pr *models.PullRequest, doer *models.User, baseRepo *git.Repository) {
+	// Reload pull request information.
+	if err := pr.LoadAttributes(); err != nil {
+		log.Error("LoadAttributes: %v", err)
+		return
+	}
+
+	if err := pr.LoadIssue(); err != nil {
+		log.Error("LoadAttributes: %v", err)
+		return
+	}
+
+	if err := pr.Issue.LoadRepo(); err != nil {
+		log.Error("pr.Issue.LoadRepo: %v", err)
+		return
+	}
+
+	mode, err := models.AccessLevel(doer, pr.Issue.Repo)
+	if err != nil {
+		log.Error("models.AccessLevel: %v", err)
+		return
+	}
+
+	// Merge pull request calls issue.changeStatus so we need to handle separately.
+	apiPullRequest := &api.PullRequestPayload{
+		Index:       pr.Issue.Index,
+		PullRequest: pr.APIFormat(),
+		Repository:  pr.Issue.Repo.APIFormat(mode),
+		Sender:      doer.APIFormat(),
+		Action:      api.HookIssueClosed,
+	}
+
+	err = webhook_module.PrepareWebhooks(pr.Issue.Repo, models.HookEventPullRequest, apiPullRequest)
+	if err != nil {
+		log.Error("PrepareWebhooks: %v", err)
+	}
+}
+
 func (m *webhookNotifier) NotifyPullRequestReview(pr *models.PullRequest, review *models.Review, comment *models.Comment) {
 	var reviewHookType models.HookEventType
 
diff --git a/routers/repo/pull.go b/routers/repo/pull.go
index a1a4e5e2bbe..0ff077b462d 100644
--- a/routers/repo/pull.go
+++ b/routers/repo/pull.go
@@ -716,8 +716,6 @@ func MergePullRequest(ctx *context.Context, form auth.MergePullRequestForm) {
 		return
 	}
 
-	notification.NotifyMergePullRequest(pr, ctx.User, ctx.Repo.GitRepo)
-
 	log.Trace("Pull request merged: %d", pr.ID)
 	ctx.Redirect(ctx.Repo.RepoLink + "/pulls/" + com.ToStr(pr.Index))
 }
diff --git a/services/pull/merge.go b/services/pull/merge.go
index 8ae5f029e8f..e5563a89b9e 100644
--- a/services/pull/merge.go
+++ b/services/pull/merge.go
@@ -426,29 +426,11 @@ func Merge(pr *models.PullRequest, doer *models.User, baseGitRepo *git.Repositor
 		log.Error("setMerged [%d]: %v", pr.ID, err)
 	}
 
-	if err := models.NotifyWatchers(&models.Action{
-		ActUserID: doer.ID,
-		ActUser:   doer,
-		OpType:    models.ActionMergePullRequest,
-		Content:   fmt.Sprintf("%d|%s", pr.Issue.Index, pr.Issue.Title),
-		RepoID:    pr.Issue.Repo.ID,
-		Repo:      pr.Issue.Repo,
-		IsPrivate: pr.Issue.Repo.IsPrivate,
-	}); err != nil {
-		log.Error("NotifyWatchers [%d]: %v", pr.ID, err)
-	}
+	notification.NotifyMergePullRequest(pr, doer, baseGitRepo)
 
 	// Reset cached commit count
 	cache.Remove(pr.Issue.Repo.GetCommitsCountCacheKey(pr.BaseBranch, true))
 
-	// Reload pull request information.
-	if err = pr.LoadAttributes(); err != nil {
-		log.Error("LoadAttributes: %v", err)
-		return nil
-	}
-
-	notification.NotifyIssueChangeStatus(doer, pr.Issue, true)
-
 	// Resolve cross references
 	refs, err := pr.ResolveCrossReferences()
 	if err != nil {