diff --git a/internal/services/pullreq/handlers_branch.go b/internal/services/pullreq/handlers_branch.go
index 3dceee943..89b97f404 100644
--- a/internal/services/pullreq/handlers_branch.go
+++ b/internal/services/pullreq/handlers_branch.go
@@ -24,6 +24,21 @@ import (
 func (s *Service) triggerPREventOnBranchUpdate(ctx context.Context,
 	event *events.Event[*gitevents.BranchUpdatedPayload],
 ) error {
+	// we should always update PR mergeable status check when target branch is updated.
+	// - main
+	//    |- develop
+	//         |- feature1
+	//         |- feature2
+	// when feature2 merge changes into develop branch then feature1 branch is not consistent anymore
+	// and need to run mergeable check even nothing was changed on feature1, same applies to main if someone
+	// push new commit to main then develop should merge status should be unchecked.
+	if branch, err := getBranchFromRef(event.Payload.Ref); err == nil {
+		err = s.pullreqStore.UpdateMergeCheckStatus(ctx, event.Payload.RepoID, branch, enum.MergeCheckStatusUnchecked)
+		if err != nil {
+			return err
+		}
+	}
+
 	// TODO: This function is currently executed directly on branch update event.
 	// TODO: But it should be executed after the PR's head ref has been updated.
 	// TODO: This is to make sure the commit exists on the target repository for forked repositories.
@@ -148,17 +163,11 @@ func (s *Service) forEveryOpenPR(ctx context.Context,
 	repoID int64, ref string,
 	fn func(pr *types.PullReq) error,
 ) {
-	const refPrefix = "refs/heads/"
 	const largeLimit = 1000000
 
-	if !strings.HasPrefix(ref, refPrefix) {
-		log.Ctx(ctx).Error().Msg("failed to get branch name from branch ref")
-		return
-	}
-
-	branch := ref[len(refPrefix):]
+	branch, err := getBranchFromRef(ref)
 	if len(branch) == 0 {
-		log.Ctx(ctx).Error().Msg("got an empty branch name from branch ref")
+		log.Ctx(ctx).Err(err).Send()
 		return
 	}
 
@@ -182,3 +191,16 @@ func (s *Service) forEveryOpenPR(ctx context.Context,
 		}
 	}
 }
+
+func getBranchFromRef(ref string) (string, error) {
+	const refPrefix = "refs/heads/"
+	if !strings.HasPrefix(ref, refPrefix) {
+		return "", fmt.Errorf("failed to get branch name from branch ref %s", ref)
+	}
+
+	branch := ref[len(refPrefix):]
+	if len(branch) == 0 {
+		return "", fmt.Errorf("got an empty branch name from branch ref %s", ref)
+	}
+	return branch, nil
+}
diff --git a/internal/store/database.go b/internal/store/database.go
index 43027ea0c..fafd43224 100644
--- a/internal/store/database.go
+++ b/internal/store/database.go
@@ -285,6 +285,9 @@ type (
 		// It will set new values to the ActivitySeq, Version and Updated fields.
 		UpdateActivitySeq(ctx context.Context, pr *types.PullReq) (*types.PullReq, error)
 
+		// Update all PR where target branch points to new SHA
+		UpdateMergeCheckStatus(ctx context.Context, targetRepo int64, targetBranch string, status enum.MergeCheckStatus) error
+
 		// Delete the pull request.
 		Delete(ctx context.Context, id int64) error
 
diff --git a/internal/store/database/pullreq.go b/internal/store/database/pullreq.go
index 8ad4bbd44..866575daa 100644
--- a/internal/store/database/pullreq.go
+++ b/internal/store/database/pullreq.go
@@ -335,6 +335,30 @@ func (s *PullReqStore) UpdateActivitySeq(ctx context.Context, pr *types.PullReq)
 	})
 }
 
+// UpdateMergeCheckStatus updates the pull request's mergeability status for all pr which target branch points to targetBranch.
+func (s *PullReqStore) UpdateMergeCheckStatus(ctx context.Context, targetRepo int64, targetBranch string, status enum.MergeCheckStatus) error {
+	const query = `
+	UPDATE pullreqs
+	SET
+		 pullreq_updated = $1
+		,pullreq_merge_check_status = $2
+	WHERE pullreq_target_repo_id = $3 AND
+		  pullreq_target_branch = $4 AND
+		  pullreq_state not in ($5, $6)`
+
+	db := dbtx.GetAccessor(ctx, s.db)
+
+	updatedAt := time.Now()
+
+	_, err := db.ExecContext(ctx, query, updatedAt, status, targetRepo, targetBranch,
+		enum.PullReqStateClosed, enum.PullReqStateClosed)
+	if err != nil {
+		return database.ProcessSQLErrorf(err, "Failed to update mergeable status check %s in pull requests", status)
+	}
+
+	return nil
+}
+
 // Delete the pull request.
 func (s *PullReqStore) Delete(ctx context.Context, id int64) error {
 	const pullReqDelete = `DELETE FROM pullreqs WHERE pullreq_id = $1`