diff --git a/lib/behaviors/hasHashBehavior.js b/lib/behaviors/hasHashBehavior.js
new file mode 100644
index 000000000..9681f6096
--- /dev/null
+++ b/lib/behaviors/hasHashBehavior.js
@@ -0,0 +1,77 @@
+'use strict';
+
+const hash256 = require('bcrypto/lib/hash256');
+const util = require('../utils/util');
+
+class HasHashBehavior {
+
+  constructor() {
+    this._hash = null;
+    this._hhash = null;
+    this._rhash = null;
+    this._whash = null;
+  }
+
+   /**
+   * Clear any cached values (abstract).
+   */
+
+  _refresh() {
+    this._hash = null;
+    this._hhash = null;
+    this._rhash = null;
+    this._whash = null;
+  }
+
+  /**
+   * Clear any cached values.
+   */
+
+  refresh() {
+    return this._refresh();
+  }
+
+  /**
+   * Get little-endian block hash.
+   * @returns {Hash}
+   */
+
+  rhash() {
+    return util.revHex(this.hash());
+  }
+
+  /**
+   * Hash the block headers.
+   * @param {Function} serializedBufferProviderFunc
+   * @param {String?} enc - Can be `'hex'` or `null`.
+   * @returns {Hash|Buffer} hash
+   */
+
+  setHash(serializedBufferProviderFunc, enc) {
+    let h = this._hash;
+
+    if (!h) {
+      h = hash256.digest(serializedBufferProviderFunc());
+      if (!this.mutable)
+        this._hash = h;
+    }
+
+    if (enc === 'hex') {
+      let hex = this._hhash;
+      if (!hex) {
+        hex = h.toString('hex');
+        if (!this.mutable)
+          this._hhash = hex;
+      }
+      h = hex;
+    }
+
+    return h;
+  }
+}
+
+/*
+ * Expose
+ */
+
+module.exports = HasHashBehavior;
diff --git a/lib/primitives/abstractblock.js b/lib/primitives/abstractblock.js
index 5cc7a63c4..227912038 100644
--- a/lib/primitives/abstractblock.js
+++ b/lib/primitives/abstractblock.js
@@ -13,6 +13,7 @@ const bio = require('bufio');
 const util = require('../utils/util');
 const InvItem = require('./invitem');
 const consensus = require('../protocol/consensus');
+const HasHashBehavior = require('../behaviors/hasHashBehavior');
 
 /**
  * Abstract Block
@@ -27,13 +28,14 @@ const consensus = require('../protocol/consensus');
  * @property {Number} nonce
  */
 
-class AbstractBlock {
+class AbstractBlock extends HasHashBehavior {
   /**
    * Create an abstract block.
    * @constructor
    */
 
   constructor() {
+    super();
     this.version = 1;
     this.prevBlock = consensus.ZERO_HASH;
     this.merkleRoot = consensus.ZERO_HASH;
@@ -42,9 +44,6 @@ class AbstractBlock {
     this.nonce = 0;
 
     this.mutable = false;
-
-    this._hash = null;
-    this._hhash = null;
   }
 
   /**
@@ -111,23 +110,6 @@ class AbstractBlock {
     return false;
   }
 
-  /**
-   * Clear any cached values (abstract).
-   */
-
-  _refresh() {
-    this._hash = null;
-    this._hhash = null;
-  }
-
-  /**
-   * Clear any cached values.
-   */
-
-  refresh() {
-    return this._refresh();
-  }
-
   /**
    * Hash the block headers.
    * @param {String?} enc - Can be `'hex'` or `null`.
@@ -135,25 +117,7 @@ class AbstractBlock {
    */
 
   hash(enc) {
-    let h = this._hash;
-
-    if (!h) {
-      h = hash256.digest(this.toHead());
-      if (!this.mutable)
-        this._hash = h;
-    }
-
-    if (enc === 'hex') {
-      let hex = this._hhash;
-      if (!hex) {
-        hex = h.toString('hex');
-        if (!this.mutable)
-          this._hhash = hex;
-      }
-      h = hex;
-    }
-
-    return h;
+    return super.setHash(this.toHead.bind(this), enc);
   }
 
   /**
@@ -238,14 +202,6 @@ class AbstractBlock {
     throw new Error('Abstract method.');
   }
 
-  /**
-   * Get little-endian block hash.
-   * @returns {Hash}
-   */
-
-  rhash() {
-    return util.revHex(this.hash());
-  }
 
   /**
    * Convert the block to an inv item.
diff --git a/lib/primitives/tx.js b/lib/primitives/tx.js
index fe4c0b069..a53d35df4 100644
--- a/lib/primitives/tx.js
+++ b/lib/primitives/tx.js
@@ -26,6 +26,7 @@ const ScriptError = require('../script/scripterror');
 const {encoding} = bio;
 const {hashType} = Script;
 const {inspectSymbol} = require('../utils');
+const HasHashBehavior = require('../behaviors/hasHashBehavior');
 
 /**
  * TX
@@ -37,7 +38,7 @@ const {inspectSymbol} = require('../utils');
  * @property {Number} locktime
  */
 
-class TX {
+class TX extends HasHashBehavior {
   /**
    * Create a transaction.
    * @constructor
@@ -45,6 +46,7 @@ class TX {
    */
 
   constructor(options) {
+    super();
     this.version = 1;
     this.inputs = [];
     this.outputs = [];
@@ -52,10 +54,6 @@ class TX {
 
     this.mutable = false;
 
-    this._hash = null;
-    this._hhash = null;
-    this._whash = null;
-
     this._raw = null;
     this._offset = -1;
     this._block = false;
@@ -153,9 +151,7 @@ class TX {
    */
 
   refresh() {
-    this._hash = null;
-    this._hhash = null;
-    this._whash = null;
+    super.refresh();
 
     this._raw = null;
     this._size = -1;
@@ -176,25 +172,7 @@ class TX {
    */
 
   hash(enc) {
-    let h = this._hash;
-
-    if (!h) {
-      h = hash256.digest(this.toNormal());
-      if (!this.mutable)
-        this._hash = h;
-    }
-
-    if (enc === 'hex') {
-      let hex = this._hhash;
-      if (!hex) {
-        hex = h.toString('hex');
-        if (!this.mutable)
-          this._hhash = hex;
-      }
-      h = hex;
-    }
-
-    return h;
+    return super.setHash(this.toNormal.bind(this), enc);
   }
 
   /**
@@ -2016,15 +1994,6 @@ class TX {
     return false;
   }
 
-  /**
-   * Get little-endian tx hash.
-   * @returns {Hash}
-   */
-
-  rhash() {
-    return util.revHex(this.hash());
-  }
-
   /**
    * Get little-endian wtx hash.
    * @returns {Hash}