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 8a0a54796..397277e94 100644
--- a/core/src/main/java/com/google/bitcoin/core/Wallet.java
+++ b/core/src/main/java/com/google/bitcoin/core/Wallet.java
@@ -232,7 +232,7 @@ public class Wallet implements Serializable {
         int size2 = unspent.size() + spent.size() + pendingInactive.size() + dead.size();
         if (size1 != size2) {
             log.error("Inconsistent wallet sizes: {} {}", size1, size2);
-            success = true;
+            success = false;
         }
         
         for (Transaction tx : unspent.values()) {
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 f1566fa7d..826ffc8ff 100644
--- a/core/src/test/java/com/google/bitcoin/core/WalletTest.java
+++ b/core/src/test/java/com/google/bitcoin/core/WalletTest.java
@@ -16,6 +16,7 @@
 
 package com.google.bitcoin.core;
 
+import com.google.bitcoin.core.WalletTransaction.Pool;
 import com.google.bitcoin.store.BlockStore;
 import com.google.bitcoin.store.MemoryBlockStore;
 import com.google.bitcoin.store.WalletProtobufSerializer;
@@ -263,6 +264,55 @@ public class WalletTest {
         assertEquals(BigInteger.ZERO.subtract(toNanoCoins(0, 10)), send2.getValue(wallet));
     }
 
+    @Test
+    public void isConsistent_duplicates() throws Exception {
+        // This test ensures that isConsistent catches duplicate transactions.
+        Transaction tx = createFakeTx(params, Utils.toNanoCoins(1, 0), myAddress);
+        Address someOtherGuy = new ECKey().toAddress(params);
+        TransactionOutput output = new TransactionOutput(params, tx, Utils.toNanoCoins(0, 5), someOtherGuy);
+        tx.addOutput(output);
+        wallet.receiveFromBlock(tx, null, BlockChain.NewBlockType.BEST_CHAIN);
+        
+        assertTrue(wallet.isConsistent());
+        
+        Transaction txClone = new Transaction(params, tx.bitcoinSerialize());
+        try {
+            wallet.receiveFromBlock(txClone, null, BlockChain.NewBlockType.SIDE_CHAIN);
+            fail();
+        } catch (IllegalStateException ex) {
+            // expected
+        }
+    }
+
+    @Test
+    public void isConsistent_pools() throws Exception {
+        // This test ensures that isConsistent catches transactions that are in incompatible pools.
+        Transaction tx = createFakeTx(params, Utils.toNanoCoins(1, 0), myAddress);
+        Address someOtherGuy = new ECKey().toAddress(params);
+        TransactionOutput output = new TransactionOutput(params, tx, Utils.toNanoCoins(0, 5), someOtherGuy);
+        tx.addOutput(output);
+        wallet.receiveFromBlock(tx, null, BlockChain.NewBlockType.BEST_CHAIN);
+        
+        assertTrue(wallet.isConsistent());
+        
+        wallet.addWalletTransaction(new WalletTransaction(Pool.PENDING, tx));
+        assertFalse(wallet.isConsistent());
+    }
+
+    @Test
+    public void isConsistent_spent() throws Exception {
+        // This test ensures that isConsistent catches transactions that are marked spent when
+        // they aren't.
+        Transaction tx = createFakeTx(params, Utils.toNanoCoins(1, 0), myAddress);
+        Address someOtherGuy = new ECKey().toAddress(params);
+        TransactionOutput output = new TransactionOutput(params, tx, Utils.toNanoCoins(0, 5), someOtherGuy);
+        tx.addOutput(output);
+        assertTrue(wallet.isConsistent());
+        
+        wallet.addWalletTransaction(new WalletTransaction(Pool.SPENT, tx));
+        assertFalse(wallet.isConsistent());
+    }
+
     @Test
     public void transactions() throws Exception {
         // This test covers a bug in which Transaction.getValueSentFromMe was calculating incorrectly.