diff --git a/core/blockchain.go b/core/blockchain.go
index 3d38b5f9f3..753a9602df 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -2302,7 +2302,7 @@ func (bc *BlockChain) maintainTxIndex(ancients uint64) {
 			} else {
 				// Prune all stale tx indices and record the tx index tail
 				log.Info("Scheduled blocks & transactions unindexing", "from block", 0, "to", head-bc.txLookupLimit+1)
-				rawdb.UnindexTransactions(bc.db, 0, head-bc.txLookupLimit+1, bc.quit)
+				rawdb.UnindexTransactions(bc.db, 0, head-bc.txLookupLimit+1, bc.quit, bc.cacheConfig.AncientPrune)
 			}
 			return
 		}
@@ -2327,7 +2327,7 @@ func (bc *BlockChain) maintainTxIndex(ancients uint64) {
 		} else {
 			// Unindex a part of stale indices and forward index tail to HEAD-limit
 			log.Info("Scheduled blocks & transactions unindexing", "from block", *tail, "to", head-bc.txLookupLimit+1)
-			rawdb.UnindexTransactions(bc.db, *tail, head-bc.txLookupLimit+1, bc.quit)
+			rawdb.UnindexTransactions(bc.db, *tail, head-bc.txLookupLimit+1, bc.quit, bc.cacheConfig.AncientPrune)
 		}
 	}
 
diff --git a/core/rawdb/chain_iterator.go b/core/rawdb/chain_iterator.go
index 4d4e42b9dc..04f10036d7 100644
--- a/core/rawdb/chain_iterator.go
+++ b/core/rawdb/chain_iterator.go
@@ -273,7 +273,7 @@ func indexTransactionsForTesting(db ethdb.Database, from uint64, to uint64, inte
 //
 // There is a passed channel, the whole procedure will be interrupted if any
 // signal received.
-func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan struct{}, hook func(uint64) bool) {
+func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan struct{}, hook func(uint64) bool, unindexBlock bool) {
 	// short circuit for invalid range
 	if from >= to {
 		return
@@ -308,7 +308,7 @@ func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt ch
 			DeleteTxLookupEntries(batch, delivery.hashes)
 			txs += len(delivery.hashes)
 			// Delete all about the block
-			if delivery.number != 0 { // never delete the genesis block
+			if unindexBlock && delivery.number != 0 { // never delete the genesis block
 				DeleteBlock(batch, delivery.blockHash, delivery.number)
 			}
 			blocks++
@@ -352,11 +352,11 @@ func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt ch
 //
 // There is a passed channel, the whole procedure will be interrupted if any
 // signal received.
-func UnindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan struct{}) {
-	unindexTransactions(db, from, to, interrupt, nil)
+func UnindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan struct{}, unindexBlock bool) {
+	unindexTransactions(db, from, to, interrupt, nil, unindexBlock)
 }
 
 // unindexTransactionsForTesting is the internal debug version with an additional hook.
 func unindexTransactionsForTesting(db ethdb.Database, from uint64, to uint64, interrupt chan struct{}, hook func(uint64) bool) {
-	unindexTransactions(db, from, to, interrupt, hook)
+	unindexTransactions(db, from, to, interrupt, hook, false)
 }
diff --git a/core/rawdb/chain_iterator_test.go b/core/rawdb/chain_iterator_test.go
index e1f5159753..15d94598fa 100644
--- a/core/rawdb/chain_iterator_test.go
+++ b/core/rawdb/chain_iterator_test.go
@@ -169,11 +169,11 @@ func TestIndexTransactions(t *testing.T) {
 	IndexTransactions(chainDb, 0, 5, nil)
 	verify(0, 11, true, 0)
 
-	UnindexTransactions(chainDb, 0, 5, nil)
+	UnindexTransactions(chainDb, 0, 5, nil, false)
 	verify(5, 11, true, 5)
 	verify(0, 5, false, 5)
 
-	UnindexTransactions(chainDb, 5, 11, nil)
+	UnindexTransactions(chainDb, 5, 11, nil, false)
 	verify(0, 11, false, 11)
 
 	// Testing corner cases