diff --git a/app/api/controller/pullreq/reviewer_add.go b/app/api/controller/pullreq/reviewer_add.go
index f16aee9a0..b8653026e 100644
--- a/app/api/controller/pullreq/reviewer_add.go
+++ b/app/api/controller/pullreq/reviewer_add.go
@@ -98,6 +98,7 @@ func (c *Controller) ReviewerAdd(
 	}
 
 	var reviewer *types.PullReqReviewer
+	var added bool
 
 	err = c.tx.WithTx(ctx, func(ctx context.Context) error {
 		reviewer, err = c.reviewerStore.Find(ctx, pr.ID, in.ReviewerID)
@@ -110,6 +111,7 @@ func (c *Controller) ReviewerAdd(
 		}
 
 		reviewer = newPullReqReviewer(session, pr, repo, reviewerInfo, addedByInfo, reviewerType, in)
+		added = true
 
 		return c.reviewerStore.Create(ctx, reviewer)
 	})
@@ -117,8 +119,38 @@ func (c *Controller) ReviewerAdd(
 		return nil, fmt.Errorf("failed to create pull request reviewer: %w", err)
 	}
 
+	if !added {
+		return reviewer, nil
+	}
+
+	err = func() error {
+		payload := &types.PullRequestActivityPayloadReviewerAdd{
+			PrincipalID:  reviewer.PrincipalID,
+			ReviewerType: reviewerType,
+		}
+
+		metadata := &types.PullReqActivityMetadata{
+			Mentions: &types.PullReqActivityMentionsMetadata{IDs: []int64{reviewer.PrincipalID}},
+		}
+
+		if pr, err = c.pullreqStore.UpdateActivitySeq(ctx, pr); err != nil {
+			return fmt.Errorf("failed to increment pull request activity sequence: %w", err)
+		}
+
+		_, err = c.activityStore.CreateWithPayload(ctx, pr, session.Principal.ID, payload, metadata)
+		if err != nil {
+			return fmt.Errorf("failed to create pull request activity: %w", err)
+		}
+
+		return nil
+	}()
+	if err != nil {
+		log.Ctx(ctx).Err(err).Msg("failed to write pull request activity after adding a reviewer")
+	}
+
 	c.reportReviewerAddition(ctx, session, pr, reviewer)
-	return reviewer, err
+
+	return reviewer, nil
 }
 
 func (c *Controller) reportReviewerAddition(
@@ -134,9 +166,11 @@ func (c *Controller) reportReviewerAddition(
 }
 
 // newPullReqReviewer creates new pull request reviewer object.
-func newPullReqReviewer(session *auth.Session, pullReq *types.PullReq,
+func newPullReqReviewer(
+	session *auth.Session, pullReq *types.PullReq,
 	repo *types.Repository, reviewerInfo, addedByInfo *types.PrincipalInfo,
-	reviewerType enum.PullReqReviewerType, in *ReviewerAddInput) *types.PullReqReviewer {
+	reviewerType enum.PullReqReviewerType, in *ReviewerAddInput,
+) *types.PullReqReviewer {
 	now := time.Now().UnixMilli()
 	return &types.PullReqReviewer{
 		PullReqID:      pullReq.ID,
diff --git a/app/api/controller/pullreq/reviewer_delete.go b/app/api/controller/pullreq/reviewer_delete.go
index be6cdfe15..202add6e7 100644
--- a/app/api/controller/pullreq/reviewer_delete.go
+++ b/app/api/controller/pullreq/reviewer_delete.go
@@ -74,27 +74,22 @@ func (c *Controller) ReviewerDelete(
 		return fmt.Errorf("failed to delete reviewer: %w", err)
 	}
 
-	if reviewer.ReviewDecision == enum.PullReqReviewDecisionPending {
-		// We create a pull request activity entry only if a review has actually been submitted.
-		return nil
-	}
-
-	activityPayload := &types.PullRequestActivityPayloadReviewerDelete{
-		CommitSHA:   reviewer.SHA,
-		Decision:    reviewer.ReviewDecision,
-		PrincipalID: reviewer.PrincipalID,
-	}
-
-	metadata := &types.PullReqActivityMetadata{
-		Mentions: &types.PullReqActivityMentionsMetadata{IDs: []int64{reviewer.PrincipalID}},
-	}
-
 	err = func() error {
+		payload := &types.PullRequestActivityPayloadReviewerDelete{
+			CommitSHA:   reviewer.SHA,
+			Decision:    reviewer.ReviewDecision,
+			PrincipalID: reviewer.PrincipalID,
+		}
+
+		metadata := &types.PullReqActivityMetadata{
+			Mentions: &types.PullReqActivityMentionsMetadata{IDs: []int64{reviewer.PrincipalID}},
+		}
+
 		if pr, err = c.pullreqStore.UpdateActivitySeq(ctx, pr); err != nil {
 			return fmt.Errorf("failed to increment pull request activity sequence: %w", err)
 		}
 
-		_, err = c.activityStore.CreateWithPayload(ctx, pr, session.Principal.ID, activityPayload, metadata)
+		_, err = c.activityStore.CreateWithPayload(ctx, pr, session.Principal.ID, payload, metadata)
 		if err != nil {
 			return fmt.Errorf("failed to create pull request activity: %w", err)
 		}
@@ -103,7 +98,7 @@ func (c *Controller) ReviewerDelete(
 	}()
 	if err != nil {
 		// non-critical error
-		log.Ctx(ctx).Err(err).Msgf("failed to write pull request activity after reviewer removal")
+		log.Ctx(ctx).Err(err).Msg("failed to write pull request activity after reviewer removal")
 	}
 
 	return nil
diff --git a/types/enum/pullreq.go b/types/enum/pullreq.go
index e59685dd4..d3b4d9b0c 100644
--- a/types/enum/pullreq.go
+++ b/types/enum/pullreq.go
@@ -83,6 +83,7 @@ const (
 	PullReqActivityTypeTitleChange    PullReqActivityType = "title-change"
 	PullReqActivityTypeStateChange    PullReqActivityType = "state-change"
 	PullReqActivityTypeReviewSubmit   PullReqActivityType = "review-submit"
+	PullReqActivityTypeReviewerAdd    PullReqActivityType = "reviewer-add"
 	PullReqActivityTypeReviewerDelete PullReqActivityType = "reviewer-delete"
 	PullReqActivityTypeBranchUpdate   PullReqActivityType = "branch-update"
 	PullReqActivityTypeBranchDelete   PullReqActivityType = "branch-delete"
diff --git a/types/pullreq_activity_payload.go b/types/pullreq_activity_payload.go
index c843f4428..b104c26fd 100644
--- a/types/pullreq_activity_payload.go
+++ b/types/pullreq_activity_payload.go
@@ -130,6 +130,15 @@ func (a *PullRequestActivityPayloadReviewSubmit) ActivityType() enum.PullReqActi
 	return enum.PullReqActivityTypeReviewSubmit
 }
 
+type PullRequestActivityPayloadReviewerAdd struct {
+	PrincipalID  int64                    `json:"principal_id"`
+	ReviewerType enum.PullReqReviewerType `json:"reviewer_type"`
+}
+
+func (a *PullRequestActivityPayloadReviewerAdd) ActivityType() enum.PullReqActivityType {
+	return enum.PullReqActivityTypeReviewerAdd
+}
+
 type PullRequestActivityPayloadReviewerDelete struct {
 	CommitSHA   string                     `json:"commit_sha"`
 	Decision    enum.PullReqReviewDecision `json:"decision"`