diff --git a/request_queue.go b/request_queue.go
index 0d35e9f1d..b40375dc8 100644
--- a/request_queue.go
+++ b/request_queue.go
@@ -1,6 +1,6 @@
 package sectorstorage
 
-import "container/heap"
+import "sort"
 
 type requestQueue []*workerRequest
 
@@ -24,21 +24,22 @@ func (q requestQueue) Swap(i, j int) {
 	q[j].index = j
 }
 
-func (q *requestQueue) Push(x interface{}) {
+func (q *requestQueue) Push(x *workerRequest) {
 	n := len(*q)
-	item := x.(*workerRequest)
+	item := x
 	item.index = n
 	*q = append(*q, item)
+	sort.Sort(q)
 }
 
-func (q *requestQueue) Pop() interface{} {
+func (q *requestQueue) Remove(i int) *workerRequest {
 	old := *q
 	n := len(old)
-	item := old[n-1]
-	old[n-1] = nil  // avoid memory leak
-	item.index = -1 // for safety
+	item := old[i]
+	old[i] = old[n - 1]
+	old[n - 1] = nil
+	item.index = -1
 	*q = old[0 : n-1]
+	sort.Sort(q)
 	return item
 }
-
-var _ heap.Interface = &requestQueue{}
diff --git a/request_queue_test.go b/request_queue_test.go
index 9bf231e39..cb4a5d5dd 100644
--- a/request_queue_test.go
+++ b/request_queue_test.go
@@ -1,7 +1,7 @@
 package sectorstorage
 
 import (
-	"container/heap"
+	"fmt"
 	"testing"
 
 	"github.com/filecoin-project/sector-storage/sealtasks"
@@ -10,19 +10,51 @@ import (
 func TestRequestQueue(t *testing.T) {
 	rq := &requestQueue{}
 
-	heap.Push(rq, &workerRequest{taskType: sealtasks.TTAddPiece})
-	heap.Push(rq, &workerRequest{taskType: sealtasks.TTPreCommit1})
-	heap.Push(rq, &workerRequest{taskType: sealtasks.TTPreCommit2})
-	heap.Push(rq, &workerRequest{taskType: sealtasks.TTPreCommit1})
-	heap.Push(rq, &workerRequest{taskType: sealtasks.TTAddPiece})
+	rq.Push(&workerRequest{taskType: sealtasks.TTAddPiece})
+	rq.Push(&workerRequest{taskType: sealtasks.TTPreCommit1})
+	rq.Push(&workerRequest{taskType: sealtasks.TTPreCommit2})
+	rq.Push(&workerRequest{taskType: sealtasks.TTPreCommit1})
+	rq.Push(&workerRequest{taskType: sealtasks.TTAddPiece})
 
-	pt := heap.Pop(rq).(*workerRequest)
+	dump := func(s string) {
+		fmt.Println("---")
+		fmt.Println(s)
+
+		for sqi := 0; sqi < rq.Len(); sqi++ {
+			task := (*rq)[sqi]
+			fmt.Println(sqi, task.taskType)
+		}
+	}
+
+	dump("start")
+
+	pt := rq.Remove(0)
+
+	dump("pop 1")
 
 	if pt.taskType != sealtasks.TTPreCommit2 {
 		t.Error("expected precommit2, got", pt.taskType)
 	}
 
-	pt = heap.Pop(rq).(*workerRequest)
+	pt = rq.Remove(0)
+
+	dump("pop 2")
+
+	if pt.taskType != sealtasks.TTPreCommit1 {
+		t.Error("expected precommit1, got", pt.taskType)
+	}
+
+	pt = rq.Remove(1)
+
+	dump("pop 3")
+
+	if pt.taskType != sealtasks.TTAddPiece {
+		t.Error("expected addpiece, got", pt.taskType)
+	}
+
+	pt = rq.Remove(0)
+
+	dump("pop 4")
 
 	if pt.taskType != sealtasks.TTPreCommit1 {
 		t.Error("expected precommit1, got", pt.taskType)
diff --git a/sched.go b/sched.go
index 239b52063..b549eb7c9 100644
--- a/sched.go
+++ b/sched.go
@@ -1,7 +1,6 @@
 package sectorstorage
 
 import (
-	"container/heap"
 	"context"
 	"fmt"
 	"math/rand"
@@ -222,7 +221,7 @@ func (sh *scheduler) runSched() {
 			sh.dropWorker(wid)
 
 		case req := <-sh.schedule:
-			heap.Push(sh.schedQueue, req)
+			sh.schedQueue.Push(req)
 			sh.trySched()
 
 			if sh.testSync != nil {
@@ -381,7 +380,7 @@ func (sh *scheduler) trySched() {
 
 		windows[selectedWindow].todo = append(windows[selectedWindow].todo, task)
 
-		heap.Remove(sh.schedQueue, sqi)
+		sh.schedQueue.Remove(sqi)
 		sqi--
 		scheduled++
 	}