diff --git a/tools/src/main/java/com/google/bitcoin/tools/BuildCheckpoints.java b/tools/src/main/java/com/google/bitcoin/tools/BuildCheckpoints.java
index c6cb7247..a910bdad 100644
--- a/tools/src/main/java/com/google/bitcoin/tools/BuildCheckpoints.java
+++ b/tools/src/main/java/com/google/bitcoin/tools/BuildCheckpoints.java
@@ -8,6 +8,7 @@ import com.google.bitcoin.utils.BriefLogFormatter;
 import com.google.bitcoin.utils.Threading;
 
 import java.io.DataOutputStream;
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.net.InetAddress;
@@ -24,18 +25,21 @@ import static com.google.common.base.Preconditions.checkState;
  * to a file which is then signed with your key.
  */
 public class BuildCheckpoints {
+
+    private static final NetworkParameters PARAMS = MainNetParams.get();
+    private static final File CHECKPOINTS_FILE = new File("checkpoints");
+
     public static void main(String[] args) throws Exception {
         BriefLogFormatter.init();
-        final NetworkParameters params = MainNetParams.get();
 
         // Sorted map of UNIX time of block to StoredBlock object.
         final TreeMap<Integer, StoredBlock> checkpoints = new TreeMap<Integer, StoredBlock>();
 
         // Configure bitcoinj to fetch only headers, not save them to disk, connect to a local fully synced/validated
         // node and to save block headers that are on interval boundaries, as long as they are <1 month old.
-        final BlockStore store = new MemoryBlockStore(params);
-        final BlockChain chain = new BlockChain(params, store);
-        final PeerGroup peerGroup = new PeerGroup(params, chain);
+        final BlockStore store = new MemoryBlockStore(PARAMS);
+        final BlockChain chain = new BlockChain(PARAMS, store);
+        final PeerGroup peerGroup = new PeerGroup(PARAMS, chain);
         peerGroup.addAddress(InetAddress.getLocalHost());
         long now = new Date().getTime() / 1000;
         peerGroup.setFastCatchupTimeSecs(now);
@@ -46,7 +50,7 @@ public class BuildCheckpoints {
             @Override
             public void notifyNewBestBlock(StoredBlock block) throws VerificationException {
                 int height = block.getHeight();
-                if (height % params.getInterval() == 0 && block.getHeader().getTimeSeconds() <= oneMonthAgo) {
+                if (height % PARAMS.getInterval() == 0 && block.getHeader().getTimeSeconds() <= oneMonthAgo) {
                     System.out.println(String.format("Checkpointing block %s at height %d",
                             block.getHeader().getHash(), block.getHeight()));
                     checkpoints.put(height, block);
@@ -60,7 +64,7 @@ public class BuildCheckpoints {
         checkState(checkpoints.size() > 0);
 
         // Write checkpoint data out.
-        final FileOutputStream fileOutputStream = new FileOutputStream("checkpoints", false);
+        final FileOutputStream fileOutputStream = new FileOutputStream(CHECKPOINTS_FILE, false);
         MessageDigest digest = MessageDigest.getInstance("SHA-256");
         final DigestOutputStream digestOutputStream = new DigestOutputStream(fileOutputStream, digest);
         digestOutputStream.on(false);
@@ -85,10 +89,12 @@ public class BuildCheckpoints {
         store.close();
 
         // Sanity check the created file.
-        CheckpointManager manager = new CheckpointManager(params, new FileInputStream("checkpoints"));
+        CheckpointManager manager = new CheckpointManager(PARAMS, new FileInputStream(CHECKPOINTS_FILE));
         checkState(manager.numCheckpoints() == checkpoints.size());
         StoredBlock test = manager.getCheckpointBefore(1348310800);  // Just after block 200,000
         checkState(test.getHeight() == 199584);
         checkState(test.getHeader().getHashAsString().equals("000000000000002e00a243fe9aa49c78f573091d17372c2ae0ae5e0f24f55b52"));
+
+        System.out.println("Checkpoints written to '" + CHECKPOINTS_FILE.getCanonicalPath() + "'.");
     }
 }