diff --git a/lib/services/address/encoding.js b/lib/services/address/encoding.js
index 81421a18..ad4b55eb 100644
--- a/lib/services/address/encoding.js
+++ b/lib/services/address/encoding.js
@@ -19,6 +19,15 @@ exports.encodeSpentIndexSyncKey = function(txidBuffer, outputIndex) {
   return key.toString('binary');
 };
 
+exports.encodeMempoolAddressIndexKey = function(hashBuffer, hashTypeBuffer) {
+  var key = Buffer.concat([
+    hashBuffer,
+    hashTypeBuffer,
+  ]);
+  return key;
+};
+
+
 exports.encodeOutputKey = function(hashBuffer, hashTypeBuffer, height, txidBuffer, outputIndex) {
   var heightBuffer = new Buffer(4);
   heightBuffer.writeUInt32BE(height);
diff --git a/lib/services/address/index.js b/lib/services/address/index.js
index da903766..b5a98e18 100644
--- a/lib/services/address/index.js
+++ b/lib/services/address/index.js
@@ -307,12 +307,12 @@ AddressService.prototype.updateMempoolIndex = function(tx, add, callback) {
       continue;
     }
 
-    var hashBufferHex = addressInfo.hashBuffer.toString('hex');
+    var addressIndexKey = encoding.encodeMempoolAddressIndexKey(addressInfo.hashBuffer, addressInfo.hashTypeBuffer);
 
     if(add) {
-      this.mempoolAddressIndex[hashBufferHex] = true;
+      this.mempoolAddressIndex[addressIndexKey] = true;
     } else {
-      delete this.mempoolAddressIndex[hashBufferHex];
+      delete this.mempoolAddressIndex[addressIndexKey];
     }
 
     // Update output index
@@ -407,11 +407,12 @@ AddressService.prototype.updateMempoolIndex = function(tx, add, callback) {
       value: inputValue
     });
 
-    var inputHashBufferHex = inputHashBuffer.toString('hex');
+    var addressIndexKey = encoding.encodeMempoolAddressIndexKey(inputHashBuffer, inputHashType);
+
     if(add) {
-      this.mempoolAddressIndex[inputHashBufferHex] = true;
+      this.mempoolAddressIndex[addressIndexKey] = true;
     } else {
-      delete this.mempoolAddressIndex[inputHashBufferHex];
+      delete this.mempoolAddressIndex[addressIndexKey];
     }
   }
 
@@ -1523,9 +1524,9 @@ AddressService.prototype._getAddressMempoolSummary = function(address, options,
   var addressStr = address.toString();
   var hashBuffer = address.hashBuffer;
   var hashTypeBuffer = constants.HASH_TYPES_MAP[address.type];
-  var hashBufferHex = hashBuffer.toString('hex');
+  var addressIndexKey = encoding.encodeMempoolAddressIndexKey(hashBuffer, hashTypeBuffer);
 
-  if(!this.mempoolAddressIndex[hashBufferHex]) {
+  if(!this.mempoolAddressIndex[addressIndexKey]) {
     return callback(null, result);
   }
 
diff --git a/test/services/address/history.unit.js b/test/services/address/history.unit.js
index ab3ee5c8..4c6306dd 100644
--- a/test/services/address/history.unit.js
+++ b/test/services/address/history.unit.js
@@ -122,7 +122,7 @@ describe('Address Service History', function() {
       history.get(function() {
         history.node.services.address.getAddressSummary.callCount.should.equal(1);
         history.node.services.address.getAddressSummary.args[0][0].should.equal(address);
-        history.node.services.address.getAddressSummary.args[0][1].should.equal({
+        history.node.services.address.getAddressSummary.args[0][1].should.deep.equal({
           noBalance: true,
         });
         history._paginateWithDetails.callCount.should.equal(1);
@@ -157,6 +157,7 @@ describe('Address Service History', function() {
         history.node.services.address.getAddressSummary.args[0][0].should.equal(address);
         history.node.services.address.getAddressSummary.args[0][1].should.deep.equal({
           fullTxList: true,
+          noBalance: true,
         });
         history._paginateWithDetails.callCount.should.equal(1);
         history._paginateWithDetails.args[0][0].should.equal(txids);
diff --git a/test/services/address/index.unit.js b/test/services/address/index.unit.js
index 4d4061e1..62745395 100644
--- a/test/services/address/index.unit.js
+++ b/test/services/address/index.unit.js
@@ -2521,8 +2521,9 @@ describe('Address Service', function() {
       );
       as.mempoolSpentIndex[spentIndexSyncKey] = true;
 
-      var hashBufferHex = address.hashBuffer.toString('hex');
-      as.mempoolAddressIndex[hashBufferHex] = true;
+      var hashTypeBuffer = constants.HASH_TYPES_MAP[address.type];
+      var addressIndex = encoding.encodeMempoolAddressIndexKey(address.hashBuffer, hashTypeBuffer);
+      as.mempoolAddressIndex[addressIndex] = true;
 
       as._getInputsMempool = sinon.stub().callsArgWith(3, null, mempoolInputs);
       as._getOutputsMempool = sinon.stub().callsArgWith(3, null, mempoolOutputs);