diff --git a/ethereum/core/src/integration-test/java/org/hyperledger/besu/ethereum/worldstate/PrunerIntegrationTest.java b/ethereum/core/src/integration-test/java/org/hyperledger/besu/ethereum/worldstate/PrunerIntegrationTest.java
index 4008ef9b66..053a4df3a3 100644
--- a/ethereum/core/src/integration-test/java/org/hyperledger/besu/ethereum/worldstate/PrunerIntegrationTest.java
+++ b/ethereum/core/src/integration-test/java/org/hyperledger/besu/ethereum/worldstate/PrunerIntegrationTest.java
@@ -123,6 +123,10 @@ public class PrunerIntegrationTest {
       generateBlockchainData(numBlockInCycle, accountsPerBlock);
       assertThat(pruner.getState()).isEqualByComparingTo(Pruner.State.IDLE);
 
+      // Restarting the Pruner shouldn't matter since we're idle
+      pruner.stop();
+      pruner.start();
+
       // Collect the nodes we expect to keep
       final Set<BytesValue> expectedNodes = new HashSet<>();
       for (int i = fullyMarkedBlockNum; i <= blockchain.getChainHeadBlockNumber(); i++) {
diff --git a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/MarkSweepPruner.java b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/MarkSweepPruner.java
index 951e265de7..b240af7766 100644
--- a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/MarkSweepPruner.java
+++ b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/MarkSweepPruner.java
@@ -97,14 +97,12 @@ public class MarkSweepPruner {
   }
 
   public void prepare() {
-    worldStateStorage.removeNodeAddedListener(nodeAddedListenerId); // Just in case.
-    markStorage.clear();
-    pendingMarks.clear();
-    nodeAddedListenerId = worldStateStorage.addNodeAddedListener(this::markNodes);
-  }
+    // Optimization for the case where the previous cycle was interrupted (like the node was shut
+    // down). If the previous cycle was interrupted, there will be marks in the mark storage from
+    // last time, causing the first sweep to be smaller than it needs to be.
+    clearMarks();
 
-  public void cleanup() {
-    worldStateStorage.removeNodeAddedListener(nodeAddedListenerId);
+    nodeAddedListenerId = worldStateStorage.addNodeAddedListener(this::markNodes);
   }
 
   public void mark(final Hash rootHash) {
@@ -151,9 +149,18 @@ public class MarkSweepPruner {
     // Sweep non-state-root nodes
     prunedNodeCount += worldStateStorage.prune(this::isMarked);
     sweptNodesCounter.inc(prunedNodeCount);
+    clearMarks();
+    LOG.debug("Completed sweeping unused nodes");
+  }
+
+  public void cleanup() {
     worldStateStorage.removeNodeAddedListener(nodeAddedListenerId);
+    clearMarks();
+  }
+
+  public void clearMarks() {
     markStorage.clear();
-    LOG.debug("Completed sweeping unused nodes");
+    pendingMarks.clear();
   }
 
   private boolean isMarked(final Bytes32 key) {
@@ -190,7 +197,14 @@ public class MarkSweepPruner {
 
   @VisibleForTesting
   void markNode(final Bytes32 hash) {
-    markNodes(Collections.singleton(hash));
+    markedNodesCounter.inc();
+    markLock.lock();
+    try {
+      pendingMarks.add(hash);
+      maybeFlushPendingMarks();
+    } finally {
+      markLock.unlock();
+    }
   }
 
   private void markNodes(final Collection<Bytes32> nodeHashes) {
@@ -210,7 +224,7 @@ public class MarkSweepPruner {
     }
   }
 
-  void flushPendingMarks() {
+  private void flushPendingMarks() {
     markLock.lock();
     try {
       final KeyValueStorageTransaction transaction = markStorage.startTransaction();
diff --git a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/Pruner.java b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/Pruner.java
index fb8c7e5116..aebd198830 100644
--- a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/Pruner.java
+++ b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/worldstate/Pruner.java
@@ -35,6 +35,7 @@ public class Pruner {
   private final MarkSweepPruner pruningStrategy;
   private final Blockchain blockchain;
   private final ExecutorService executorService;
+  private Long blockAddedObserverId;
   private final long blocksRetained;
   private final AtomicReference<State> state = new AtomicReference<>(State.IDLE);
   private volatile long markBlockNumber = 0;
@@ -58,11 +59,14 @@ public class Pruner {
 
   public void start() {
     LOG.info("Starting Pruner.");
-    blockchain.observeBlockAdded((event, blockchain) -> handleNewBlock(event));
+    pruningStrategy.prepare();
+    blockAddedObserverId =
+        blockchain.observeBlockAdded((event, blockchain) -> handleNewBlock(event));
   }
 
   public void stop() throws InterruptedException {
     pruningStrategy.cleanup();
+    blockchain.removeObserver(blockAddedObserverId);
     executorService.awaitTermination(10, TimeUnit.SECONDS);
   }
 
@@ -73,7 +77,6 @@ public class Pruner {
 
     final long blockNumber = event.getBlock().getHeader().getNumber();
     if (state.compareAndSet(State.IDLE, State.MARK_BLOCK_CONFIRMATIONS_AWAITING)) {
-      pruningStrategy.prepare();
       markBlockNumber = blockNumber;
     } else if (blockNumber >= markBlockNumber + blockConfirmations
         && state.compareAndSet(State.MARK_BLOCK_CONFIRMATIONS_AWAITING, State.MARKING)) {
@@ -87,7 +90,6 @@ public class Pruner {
   }
 
   private void mark(final BlockHeader header) {
-    markBlockNumber = header.getNumber();
     final Hash stateRoot = header.getStateRoot();
     LOG.debug(
         "Begin marking used nodes for pruning. Block number: {} State root: {}",
@@ -117,6 +119,7 @@ public class Pruner {
       executorService.execute(action);
     } catch (final Throwable t) {
       LOG.error("Pruning failed", t);
+      pruningStrategy.cleanup();
       state.set(State.IDLE);
     }
   }
diff --git a/ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/DefaultSynchronizer.java b/ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/DefaultSynchronizer.java
index ad9b013a73..51004654d8 100644
--- a/ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/DefaultSynchronizer.java
+++ b/ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/DefaultSynchronizer.java
@@ -170,8 +170,8 @@ public class DefaultSynchronizer<C> implements Synchronizer {
   }
 
   private void startFullSync() {
-    fullSyncDownloader.start();
     maybePruner.ifPresent(Pruner::start);
+    fullSyncDownloader.start();
   }
 
   @Override