diff --git a/lib/bcoin/merkleblock.js b/lib/bcoin/merkleblock.js
index 4cdd7c2c..8e96ee22 100644
--- a/lib/bcoin/merkleblock.js
+++ b/lib/bcoin/merkleblock.js
@@ -50,6 +50,7 @@ function MerkleBlock(data) {
   // List of matched TXs
   this.txMap = {};
   this.tx = [];
+  this._partialVerified = null;
 
   // TXs that will be pushed on
   this.txs = [];
@@ -118,6 +119,8 @@ MerkleBlock.prototype.hasTX = function hasTX(hash) {
   if (hash instanceof bcoin.tx)
     hash = hash.hash('hex');
 
+  this.verifyPartial();
+
   return this.txMap[hash] === true;
 };
 
@@ -128,7 +131,7 @@ MerkleBlock.prototype.hasTX = function hasTX(hash) {
  * @returns {Boolean}
  */
 
-MerkleBlock.prototype._verifyPartial = function _verifyPartial() {
+MerkleBlock.prototype.verifyPartial = function verifyPartial() {
   var height = 0;
   var tx = [];
   var txMap = {};
@@ -137,6 +140,9 @@ MerkleBlock.prototype._verifyPartial = function _verifyPartial() {
   var flags = this.flags;
   var i, root;
 
+  if (this._partialVerified != null)
+    return this._partialVerified;
+
   // Count leaves
   for (i = this.totalTX; i > 0; i >>= 1)
     height++;
@@ -178,11 +184,14 @@ MerkleBlock.prototype._verifyPartial = function _verifyPartial() {
 
   root = utils.toHex(visit(1));
 
-  if (!root || root !== this.merkleRoot)
+  if (!root || root !== this.merkleRoot) {
+    this._partialVerified = false;
     return false;
+  }
 
   this.tx = tx;
   this.txMap = txMap;
+  this._partialVerified = true;
 
   return true;
 };
@@ -204,7 +213,7 @@ MerkleBlock.prototype._verify = function _verify(ret) {
     return false;
 
   // Verify the partial merkle tree if we are a merkleblock.
-  if (!this._verifyPartial()) {
+  if (!this.verifyPartial()) {
     ret.reason = 'bad-txnmrklroot';
     ret.score = 100;
     return false;
@@ -389,7 +398,7 @@ MerkleBlock.fromBlock = function fromBlock(block, bloom) {
 MerkleBlock.isMerkleBlock = function isMerkleBlock(obj) {
   return obj
     && Array.isArray(obj.flags)
-    && typeof obj._verifyPartial === 'function';
+    && typeof obj.verifyPartial === 'function';
 };
 
 return MerkleBlock;