diff --git a/src/main/java/org/qortal/block/BlockChain.java b/src/main/java/org/qortal/block/BlockChain.java
index 531d3ad4..0aa6860b 100644
--- a/src/main/java/org/qortal/block/BlockChain.java
+++ b/src/main/java/org/qortal/block/BlockChain.java
@@ -482,7 +482,7 @@ public class BlockChain {
 	}
 
 	/**
-	 * Some sort start-up/initialization/checking method.
+	 * Some sort of start-up/initialization/checking method.
 	 * 
 	 * @throws SQLException
 	 */
@@ -492,7 +492,9 @@ public class BlockChain {
 			rebuildBlockchain();
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			BlockData detachedBlockData = repository.getBlockRepository().getDetachedBlockSignature();
+			int startHeight = Math.max(repository.getBlockRepository().getBlockchainHeight() - 1440, 1);
+
+			BlockData detachedBlockData = repository.getBlockRepository().getDetachedBlockSignature(startHeight);
 
 			if (detachedBlockData != null) {
 				LOGGER.error(String.format("Block %d's reference does not match any block's signature", detachedBlockData.getHeight()));
diff --git a/src/main/java/org/qortal/repository/BlockRepository.java b/src/main/java/org/qortal/repository/BlockRepository.java
index 078128f6..4265b71f 100644
--- a/src/main/java/org/qortal/repository/BlockRepository.java
+++ b/src/main/java/org/qortal/repository/BlockRepository.java
@@ -152,11 +152,12 @@ public interface BlockRepository {
 	public int trimOldOnlineAccountsSignatures(long timestamp) throws DataException;
 
 	/**
-	 * Returns first (lowest height) block that doesn't link back to genesis block.
+	 * Returns first (lowest height) block that doesn't link back to specified block.
 	 * 
+	 * @param startHeight height of specified block
 	 * @throws DataException
 	 */
-	public BlockData getDetachedBlockSignature() throws DataException;
+	public BlockData getDetachedBlockSignature(int startHeight) throws DataException;
 
 	/**
 	 * Saves block into repository.
diff --git a/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java b/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java
index 0486bdc7..7f3f2f7c 100644
--- a/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java
+++ b/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java
@@ -471,14 +471,14 @@ public class HSQLDBBlockRepository implements BlockRepository {
 	}
 
 	@Override
-	public BlockData getDetachedBlockSignature() throws DataException {
+	public BlockData getDetachedBlockSignature(int startHeight) throws DataException {
 		String sql = "SELECT " + BLOCK_DB_COLUMNS + " FROM Blocks "
 				+ "LEFT OUTER JOIN Blocks AS ParentBlocks "
 				+ "ON ParentBlocks.signature = Blocks.reference "
-				+ "WHERE ParentBlocks.signature IS NULL AND Blocks.height > 1 "
+				+ "WHERE ParentBlocks.signature IS NULL AND Blocks.height > ? "
 				+ "ORDER BY Blocks.height ASC LIMIT 1";
 
-		try (ResultSet resultSet = this.repository.checkedExecute(sql)) {
+		try (ResultSet resultSet = this.repository.checkedExecute(sql, startHeight)) {
 			return getBlockFromResultSet(resultSet);
 		} catch (SQLException e) {
 			throw new DataException("Error fetching block by signature from repository", e);