diff --git a/src/main/java/org/qortal/block/BlockChain.java b/src/main/java/org/qortal/block/BlockChain.java
index 809e678b..8f6ddab7 100644
--- a/src/main/java/org/qortal/block/BlockChain.java
+++ b/src/main/java/org/qortal/block/BlockChain.java
@@ -32,7 +32,6 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
-import org.qortal.utils.NTP;
 import org.qortal.utils.StringLongMapXmlAdapter;
 
 /**
@@ -578,33 +577,4 @@ public class BlockChain {
 		}
 	}
 
-	public static void trimOldOnlineAccountsSignatures() {
-		final Long now = NTP.getTime();
-		if (now == null)
-			return;
-
-		ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
-		if (!blockchainLock.tryLock())
-			// Too busy to trim right now, try again later
-			return;
-
-		try {
-			try (final Repository repository = RepositoryManager.tryRepository()) {
-				if (repository == null)
-					return;
-
-				int numBlocksTrimmed = repository.getBlockRepository().trimOldOnlineAccountsSignatures(now - BlockChain.getInstance().getOnlineAccountSignaturesMaxLifetime());
-
-				if (numBlocksTrimmed > 0)
-					LOGGER.debug(String.format("Trimmed old online accounts signatures from %d block%s", numBlocksTrimmed, (numBlocksTrimmed != 1 ? "s" : "")));
-
-				repository.saveChanges();
-			} catch (DataException e) {
-				LOGGER.warn(String.format("Repository issue trying to trim old online accounts signatures: %s", e.getMessage()));
-			}
-		} finally {
-			blockchainLock.unlock();
-		}
-	}
-
 }
diff --git a/src/main/java/org/qortal/controller/Controller.java b/src/main/java/org/qortal/controller/Controller.java
index 50db9763..4e9c6e76 100644
--- a/src/main/java/org/qortal/controller/Controller.java
+++ b/src/main/java/org/qortal/controller/Controller.java
@@ -1407,7 +1407,24 @@ public class Controller extends Thread {
 		sendOurOnlineAccountsInfo();
 
 		// Trim blockchain by removing 'old' online accounts signatures
-		BlockChain.trimOldOnlineAccountsSignatures();
+		long upperMintedTimestamp = now - BlockChain.getInstance().getOnlineAccountSignaturesMaxLifetime();
+		trimOldOnlineAccountsSignatures(upperMintedTimestamp);
+	}
+
+	private void trimOldOnlineAccountsSignatures(long upperMintedTimestamp) {
+		try (final Repository repository = RepositoryManager.tryRepository()) {
+			if (repository == null)
+				return;
+
+			int numBlocksTrimmed = repository.getBlockRepository().trimOldOnlineAccountsSignatures(upperMintedTimestamp);
+
+			if (numBlocksTrimmed > 0)
+				LOGGER.debug(() -> String.format("Trimmed old online accounts signatures from %d block%s", numBlocksTrimmed, (numBlocksTrimmed != 1 ? "s" : "")));
+
+			repository.saveChanges();
+		} catch (DataException e) {
+			LOGGER.warn(String.format("Repository issue trying to trim old online accounts signatures: %s", e.getMessage()));
+		}
 	}
 
 	private void sendOurOnlineAccountsInfo() {
diff --git a/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java b/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java
index 56f3377f..c9d9de50 100644
--- a/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java
+++ b/src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java
@@ -465,11 +465,14 @@ public class HSQLDBBlockRepository implements BlockRepository {
 
 	@Override
 	public int trimOldOnlineAccountsSignatures(long timestamp) throws DataException {
-		String sql = "UPDATE Blocks set online_accounts_signatures = NULL WHERE minted_when < ? AND online_accounts_signatures IS NOT NULL";
+		// We're often called so no need to trim all blocks in one go.
+		// Limit updates to reduce CPU and memory load.
+		String sql = "UPDATE Blocks set online_accounts_signatures = NULL WHERE minted_when < ? AND online_accounts_signatures IS NOT NULL LIMIT 1440";
 
 		try {
 			return this.repository.executeCheckedUpdate(sql, timestamp);
 		} catch (SQLException e) {
+			repository.examineException(e);
 			throw new DataException("Unable to trim old online accounts signatures in repository", e);
 		}
 	}