diff --git a/core/txpool/legacypool/legacypool.go b/core/txpool/legacypool/legacypool.go
index e2ae738355..d57ee02b3d 100644
--- a/core/txpool/legacypool/legacypool.go
+++ b/core/txpool/legacypool/legacypool.go
@@ -1569,18 +1569,6 @@ func (pool *LegacyPool) demoteUnexecutables() {
 	}
 }
 
-// addressByHeartbeat is an account address tagged with its last activity timestamp.
-type addressByHeartbeat struct {
-	address   common.Address
-	heartbeat time.Time
-}
-
-type addressesByHeartbeat []addressByHeartbeat
-
-func (a addressesByHeartbeat) Len() int           { return len(a) }
-func (a addressesByHeartbeat) Less(i, j int) bool { return a[i].heartbeat.Before(a[j].heartbeat) }
-func (a addressesByHeartbeat) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-
 // accountSet is simply a set of addresses to check for existence, and a signer
 // capable of deriving addresses from transactions.
 type accountSet struct {
diff --git a/core/txpool/legacypool/queue.go b/core/txpool/legacypool/queue.go
index 5ce0be960f..8edb03056e 100644
--- a/core/txpool/legacypool/queue.go
+++ b/core/txpool/legacypool/queue.go
@@ -240,3 +240,15 @@ func (q *queue) truncate() []common.Hash {
 	}
 	return removed
 }
+
+// addressByHeartbeat is an account address tagged with its last activity timestamp.
+type addressByHeartbeat struct {
+	address   common.Address
+	heartbeat time.Time
+}
+
+type addressesByHeartbeat []addressByHeartbeat
+
+func (a addressesByHeartbeat) Len() int           { return len(a) }
+func (a addressesByHeartbeat) Less(i, j int) bool { return a[i].heartbeat.Before(a[j].heartbeat) }
+func (a addressesByHeartbeat) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }