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 c9ac410d..b36bd649 100644
--- a/core/src/main/java/com/google/bitcoin/core/Wallet.java
+++ b/core/src/main/java/com/google/bitcoin/core/Wallet.java
@@ -3648,6 +3648,7 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
      */
     @Override
     public int getBloomFilterElementCount() {
+        checkState(lock.isHeldByCurrentThread());
         int size = keychain.getBloomFilterElementCount();
         for (Transaction tx : getTransactions(false)) {
             for (TransactionOutput out : tx.getOutputs()) {
@@ -3674,6 +3675,7 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
      */
     @Override
     public boolean isRequiringUpdateAllBloomFilter() {
+        checkState(lock.isHeldByCurrentThread());
         return !watchedScripts.isEmpty();
     }
 
@@ -3698,23 +3700,17 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
      */
     @Override
     public BloomFilter getBloomFilter(int size, double falsePositiveRate, long nTweak) {
-        BloomFilter filter;
-        lock.lock();
-        try {
-            filter = keychain.getBloomFilter(size, falsePositiveRate, nTweak);
-
-            for (Script script : watchedScripts) {
-                for (ScriptChunk chunk : script.getChunks()) {
-                    // Only add long (at least 64 bit) data to the bloom filter.
-                    // If any long constants become popular in scripts, we will need logic
-                    // here to exclude them.
-                    if (!chunk.isOpCode() && chunk.data.length >= MINIMUM_BLOOM_DATA_LENGTH) {
-                        filter.insert(chunk.data);
-                    }
+        checkState(lock.isHeldByCurrentThread());
+        BloomFilter filter = keychain.getBloomFilter(size, falsePositiveRate, nTweak);
+        for (Script script : watchedScripts) {
+            for (ScriptChunk chunk : script.getChunks()) {
+                // Only add long (at least 64 bit) data to the bloom filter.
+                // If any long constants become popular in scripts, we will need logic
+                // here to exclude them.
+                if (!chunk.isOpCode() && chunk.data.length >= MINIMUM_BLOOM_DATA_LENGTH) {
+                    filter.insert(chunk.data);
                 }
             }
-        } finally {
-            lock.unlock();
         }
         for (Transaction tx : getTransactions(false)) {
             for (int i = 0; i < tx.getOutputs().size(); i++) {