diff --git a/core/blockchain.go b/core/blockchain.go
index 8df2365072..42a8405ec9 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -2628,6 +2628,7 @@ func (bc *BlockChain) reorg(oldHead *types.Header, newHead *types.Header) error
 	// as the txlookups should be changed atomically, and all subsequent
 	// reads should be blocked until the mutation is complete.
 	bc.txLookupLock.Lock()
+	defer bc.txLookupLock.Unlock()
 
 	// Reorg can be executed, start reducing the chain's old blocks and appending
 	// the new blocks
@@ -2730,9 +2731,6 @@ func (bc *BlockChain) reorg(oldHead *types.Header, newHead *types.Header) error
 	// Reset the tx lookup cache to clear stale txlookup cache.
 	bc.txLookupCache.Purge()
 
-	// Release the tx-lookup lock after mutation.
-	bc.txLookupLock.Unlock()
-
 	return nil
 }