diff --git a/lib/bcoin/block.js b/lib/bcoin/block.js
index c5291f88..b9d4571d 100644
--- a/lib/bcoin/block.js
+++ b/lib/bcoin/block.js
@@ -339,16 +339,15 @@ Block.prototype.__defineGetter__('commitmentHash', function() {
     commitment = coinbase.outputs[i].script;
     if (commitment.isCommitment()) {
       commitmentHash = commitment.getCommitmentHash();
+      commitmentHash = commitmentHash.toString('hex');
       break;
     }
   }
 
-  if (!this.mutable) {
-    if (commitmentHash)
-      this._commitmentHash = commitmentHash.toString('hex');
-  }
+  if (!this.mutable)
+    this._commitmentHash = commitmentHash;
 
-  return this._commitmentHash;
+  return commitmentHash;
 });
 
 /**
diff --git a/lib/bcoin/miner.js b/lib/bcoin/miner.js
index c571328c..19be189c 100644
--- a/lib/bcoin/miner.js
+++ b/lib/bcoin/miner.js
@@ -100,13 +100,15 @@ Miner.prototype._init = function _init() {
     this.mempool.on('tx', function(tx) {
       if (!self.running)
         return;
-      self.attempt.addTX(tx);
+      if (self.attempt)
+        self.attempt.addTX(tx);
     });
   } else if (this.pool) {
     this.pool.on('tx', function(tx) {
       if (!self.running)
         return;
-      self.attempt.addTX(tx);
+      if (self.attempt)
+        self.attempt.addTX(tx);
     });
   }