diff --git a/lib/primitives/block.js b/lib/primitives/block.js
index 60aea44b..663d2756 100644
--- a/lib/primitives/block.js
+++ b/lib/primitives/block.js
@@ -38,7 +38,6 @@ function Block(options) {
   this.txs = [];
 
   this._cbHeight = null;
-  this._commitmentHash = null;
 
   this._raw = null;
   this._size = -1;
@@ -400,32 +399,23 @@ Block.prototype.getWitnessNonce = function getWitnessNonce() {
  */
 
 Block.prototype.getCommitmentHash = function getCommitmentHash(enc) {
-  var hash = this._commitmentHash;
-  var i, coinbase, output;
+  var coinbase = this.txs[0];
+  var i, hash, output;
 
-  if (!hash) {
-    coinbase = this.txs[0];
+  if (!coinbase)
+    return null;
 
-    if (!coinbase)
-      return null;
-
-    for (i = coinbase.outputs.length - 1; i >= 0; i--) {
-      output = coinbase.outputs[i];
-
-      if (output.script.isCommitment()) {
-        hash = output.script.getCommitmentHash();
-
-        if (!this.mutable)
-          this._commitmentHash = hash;
-
-        break;
-      }
+  for (i = coinbase.outputs.length - 1; i >= 0; i--) {
+    output = coinbase.outputs[i];
+    if (output.script.isCommitment()) {
+      hash = output.script.getCommitmentHash();
+      break;
     }
-
-    if (!hash)
-      return null;
   }
 
+  if (!hash)
+    return null;
+
   return enc === 'hex'
     ? hash.toString('hex')
     : hash;