diff --git a/core/src/main/java/com/google/bitcoin/core/Wallet.java b/core/src/main/java/com/google/bitcoin/core/Wallet.java
index c1cb7f26..af9c37a9 100644
--- a/core/src/main/java/com/google/bitcoin/core/Wallet.java
+++ b/core/src/main/java/com/google/bitcoin/core/Wallet.java
@@ -222,6 +222,8 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
     public Wallet(NetworkParameters params, KeyChainGroup keyChainGroup) {
         this.params = checkNotNull(params);
         this.keychain = checkNotNull(keyChainGroup);
+        if (params == UnitTestParams.get())
+            this.keychain.setLookaheadSize(5);  // Cut down excess computation for unit tests.
         watchedScripts = Sets.newHashSet();
         unspent = new HashMap<Sha256Hash, Transaction>();
         spent = new HashMap<Sha256Hash, Transaction>();
diff --git a/core/src/main/java/com/google/bitcoin/testing/TestWithNetworkConnections.java b/core/src/main/java/com/google/bitcoin/testing/TestWithNetworkConnections.java
index 840708ff..b0b99f83 100644
--- a/core/src/main/java/com/google/bitcoin/testing/TestWithNetworkConnections.java
+++ b/core/src/main/java/com/google/bitcoin/testing/TestWithNetworkConnections.java
@@ -85,7 +85,6 @@ public class TestWithNetworkConnections {
         Wallet.SendRequest.DEFAULT_FEE_PER_KB = BigInteger.ZERO;
         this.blockStore = blockStore;
         wallet = new Wallet(unitTestParams);
-        wallet.setKeychainLookaheadSize(5);   // Make tests faster by reducing the number of keys derived ahead of time.
         key = wallet.freshReceiveKey();
         address = key.toAddress(unitTestParams);
         blockChain = new BlockChain(unitTestParams, wallet, blockStore);
diff --git a/core/src/main/java/com/google/bitcoin/testing/TestWithWallet.java b/core/src/main/java/com/google/bitcoin/testing/TestWithWallet.java
index 0da93cb0..ad784ac6 100644
--- a/core/src/main/java/com/google/bitcoin/testing/TestWithWallet.java
+++ b/core/src/main/java/com/google/bitcoin/testing/TestWithWallet.java
@@ -20,7 +20,6 @@ import com.google.bitcoin.core.*;
 import com.google.bitcoin.params.UnitTestParams;
 import com.google.bitcoin.store.BlockStore;
 import com.google.bitcoin.store.MemoryBlockStore;
-import com.google.bitcoin.testing.FakeTxBuilder;
 import com.google.bitcoin.utils.BriefLogFormatter;
 
 import javax.annotation.Nullable;
@@ -52,7 +51,6 @@ public class TestWithWallet {
         BriefLogFormatter.init();
         Wallet.SendRequest.DEFAULT_FEE_PER_KB = BigInteger.ZERO;
         wallet = new Wallet(params);
-        wallet.setKeychainLookaheadSize(5);
         myKey = wallet.currentReceiveKey();
         myAddress = myKey.toAddress(params);
         blockStore = new MemoryBlockStore(params);
diff --git a/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java b/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java
index d6554090..28a0d2a1 100644
--- a/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java
+++ b/core/src/test/java/com/google/bitcoin/core/ChainSplitTest.java
@@ -56,7 +56,6 @@ public class ChainSplitTest {
         Wallet.SendRequest.DEFAULT_FEE_PER_KB = BigInteger.ZERO;
         unitTestParams = UnitTestParams.get();
         wallet = new Wallet(unitTestParams);
-        wallet.setKeychainLookaheadSize(5);  // Make tests faster.
         ECKey key1 = wallet.freshReceiveKey();
         ECKey key2 = wallet.freshReceiveKey();
         blockStore = new MemoryBlockStore(unitTestParams);
diff --git a/core/src/test/java/com/google/bitcoin/core/WalletTest.java b/core/src/test/java/com/google/bitcoin/core/WalletTest.java
index 6e342da3..2bb87b83 100644
--- a/core/src/test/java/com/google/bitcoin/core/WalletTest.java
+++ b/core/src/test/java/com/google/bitcoin/core/WalletTest.java
@@ -81,7 +81,6 @@ public class WalletTest extends TestWithWallet {
     public void setUp() throws Exception {
         super.setUp();
         encryptedWallet = new Wallet(params);
-        encryptedWallet.setKeychainLookaheadSize(5);  // For speed.
         myEncryptedAddress = encryptedWallet.freshReceiveKey().toAddress(params);
         encryptedWallet.encrypt(PASSWORD1);
         keyCrypter = encryptedWallet.getKeyCrypter();
@@ -990,7 +989,6 @@ public class WalletTest extends TestWithWallet {
     @Test
     public void keyCreationTime() throws Exception {
         wallet = new Wallet(params);
-        wallet.setKeychainLookaheadSize(5);  // For speed.
         Utils.setMockClock();
         long now = Utils.currentTimeSeconds();
         // No keys returns current time.
@@ -1006,7 +1004,6 @@ public class WalletTest extends TestWithWallet {
     @Test
     public void scriptCreationTime() throws Exception {
         wallet = new Wallet(params);
-        wallet.setKeychainLookaheadSize(5);  // For speed.
         Utils.setMockClock();
         long now = Utils.currentTimeSeconds();
         // No keys returns current time.
@@ -2373,7 +2370,6 @@ public class WalletTest extends TestWithWallet {
                 keys.addAll(k);
             }
         }, Threading.SAME_THREAD);
-        wallet.setKeychainLookaheadSize(5);
         wallet.freshReceiveKey();
         assertEquals(6, keys.size());
     }
diff --git a/core/src/test/java/com/google/bitcoin/protocols/channels/ChannelConnectionTest.java b/core/src/test/java/com/google/bitcoin/protocols/channels/ChannelConnectionTest.java
index 0a939dd3..29f0a51a 100644
--- a/core/src/test/java/com/google/bitcoin/protocols/channels/ChannelConnectionTest.java
+++ b/core/src/test/java/com/google/bitcoin/protocols/channels/ChannelConnectionTest.java
@@ -69,7 +69,6 @@ public class ChannelConnectionTest extends TestWithWallet {
         sendMoneyToWallet(Utils.COIN, AbstractBlockChain.NewBlockType.BEST_CHAIN);
         wallet.addExtension(new StoredPaymentChannelClientStates(wallet, failBroadcaster));
         serverWallet = new Wallet(params);
-        serverWallet.setKeychainLookaheadSize(5);
         serverWallet.addExtension(new StoredPaymentChannelServerStates(serverWallet, failBroadcaster));
         serverWallet.freshReceiveKey();
         serverChain = new BlockChain(params, serverWallet, blockStore);
@@ -544,7 +543,6 @@ public class ChannelConnectionTest extends TestWithWallet {
     @Test
     public void testEmptyWallet() throws Exception {
         Wallet emptyWallet = new Wallet(params);
-        emptyWallet.setKeychainLookaheadSize(5);
         emptyWallet.freshReceiveKey();
         ChannelTestUtils.RecordingPair pair = ChannelTestUtils.makeRecorders(serverWallet, mockBroadcaster);
         PaymentChannelServer server = pair.server;