diff --git a/server/grpc/rpc.go b/server/grpc/rpc.go
index c7ed7211f44..c4293c6abcd 100644
--- a/server/grpc/rpc.go
+++ b/server/grpc/rpc.go
@@ -71,15 +71,10 @@ func (s *RPC) Next(c context.Context, agentFilter rpc.Filter) (*rpc.Workflow, er
 	for {
 		// poll blocks until a task is available or the context is canceled / worker is kicked
 		task, err := s.queue.Poll(c, agent.ID, filterFn)
-		if err != nil {
+		if err != nil || task == nil {
 			return nil, err
 		}
 
-		// poll returns nil task if context was canceled / worker was kicked
-		if task == nil {
-			return nil, nil
-		}
-
 		if task.ShouldRun() {
 			workflow := new(rpc.Workflow)
 			err = json.Unmarshal(task.Data, workflow)
diff --git a/server/queue/fifo.go b/server/queue/fifo.go
index 7c746e3dc3d..29e24d1035e 100644
--- a/server/queue/fifo.go
+++ b/server/queue/fifo.go
@@ -17,6 +17,7 @@ package queue
 import (
 	"container/list"
 	"context"
+	"fmt"
 	"sync"
 	"time"
 
@@ -36,7 +37,7 @@ type worker struct {
 	agentID int64
 	filter  FilterFn
 	channel chan *model.Task
-	stop    context.CancelFunc
+	stop    context.CancelCauseFunc
 }
 
 type fifo struct {
@@ -85,7 +86,7 @@ func (q *fifo) PushAtOnce(_ context.Context, tasks []*model.Task) error {
 // Poll retrieves and removes a task head of this queue.
 func (q *fifo) Poll(c context.Context, agentID int64, f FilterFn) (*model.Task, error) {
 	q.Lock()
-	ctx, stop := context.WithCancel(c)
+	ctx, stop := context.WithCancelCause(c)
 
 	w := &worker{
 		agentID: agentID,
@@ -103,7 +104,7 @@ func (q *fifo) Poll(c context.Context, agentID int64, f FilterFn) (*model.Task,
 			q.Lock()
 			delete(q.workers, w)
 			q.Unlock()
-			return nil, nil
+			return nil, ctx.Err()
 		case t := <-w.channel:
 			return t, nil
 		}
@@ -244,7 +245,7 @@ func (q *fifo) KickAgentWorkers(agentID int64) {
 
 	for w := range q.workers {
 		if w.agentID == agentID {
-			w.stop()
+			w.stop(fmt.Errorf("worker was kicked"))
 			delete(q.workers, w)
 		}
 	}