diff --git a/core/txpool/list.go b/core/txpool/list.go
index eb0c753f2..062cbbf63 100644
--- a/core/txpool/list.go
+++ b/core/txpool/list.go
@@ -45,6 +45,7 @@ func (h *nonceHeap) Pop() interface{} {
 	old := *h
 	n := len(old)
 	x := old[n-1]
+	old[n-1] = 0
 	*h = old[0 : n-1]
 	return x
 }
diff --git a/core/types/transaction.go b/core/types/transaction.go
index 910c68aea..353e0e599 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -508,6 +508,7 @@ func (s *TxByPriceAndTime) Pop() interface{} {
 	old := *s
 	n := len(old)
 	x := old[n-1]
+	old[n-1] = nil
 	*s = old[0 : n-1]
 	return x
 }
diff --git a/p2p/util.go b/p2p/util.go
index 3c5f6b850..2c8f322a6 100644
--- a/p2p/util.go
+++ b/p2p/util.go
@@ -70,6 +70,7 @@ func (h *expHeap) Pop() interface{} {
 	old := *h
 	n := len(old)
 	x := old[n-1]
+	old[n-1] = expItem{}
 	*h = old[0 : n-1]
 	return x
 }