diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index 080d2076..3eb64ce0 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -277,7 +277,7 @@ MTX.prototype.scriptInput = function scriptInput(index, addr) {
     vector[0] = dummy;
 
     // Grab `n` value (number of keys).
-    n = prev.code[prev.code.length - 2] - 0x50;
+    n = Script.getSmall(prev.code[prev.code.length - 2]);
 
     // Fill script with `n` signature slots.
     for (i = 0; i < n; i++)
@@ -434,10 +434,10 @@ MTX.prototype.signInput = function signInput(index, addr, type) {
     keys = prev.code.slice(1, -2);
 
     // Grab `m` value (number of sigs required).
-    m = prev.code[0] - 0x50;
+    m = Script.getSmall(prev.code[0]);
 
     // Grab `n` value (number of keys).
-    n = prev.code[prev.code.length - 2] - 0x50;
+    n = Script.getSmall(prev.code[prev.code.length - 2]);
   } else {
     // Only allow non-standard signing for
     // scripthash.
@@ -584,7 +584,7 @@ MTX.prototype.isSigned = function isSigned(m) {
         return false;
     } else if (prev.isMultisig()) {
       // Grab `m` value (number of required sigs).
-      m = prev.code[0] - 0x50;
+      m = Script.getSmall(prev.code[0]);
 
       // Ensure all members are signatures.
       for (j = 1; j < len; j++) {
@@ -737,7 +737,7 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN) {
     } else if (prev.isMultisig()) {
       // Bare Multisig
       // Get the previous m value:
-      m = prev.code[0] - 0x50;
+      m = Script.getSmall(prev.code[0]);
       // OP_0
       size += 1;
       // OP_PUSHDATA0 [signature] ...
diff --git a/lib/bcoin/peer.js b/lib/bcoin/peer.js
index 316df468..7b094bec 100644
--- a/lib/bcoin/peer.js
+++ b/lib/bcoin/peer.js
@@ -588,21 +588,19 @@ Peer.prototype._handleGetAddr = function handleGetAddr() {
 };
 
 Peer.prototype._handleInv = function handleInv(items) {
-  var blocks, txs;
+  var blocks = [];
+  var txs = [];
+  var item, i;
 
   this.emit('inv', items);
 
-  txs = items.filter(function(item) {
-    return item.type === constants.inv.tx;
-  }).map(function(item) {
-    return item.hash;
-  });
-
-  blocks = items.filter(function(item) {
-    return item.type === constants.inv.block;
-  }).map(function(item) {
-    return item.hash;
-  });
+  for (i = 0; i < items.length; i++) {
+    item = items[i];
+    if (item.type === constants.inv.tx)
+      txs.push(item.hash);
+    else if (item.type === constants.inv.block)
+      blocks.push(item.hash);
+  }
 
   if (blocks.length > 0)
     this.emit('blocks', blocks);
@@ -620,11 +618,16 @@ Peer.prototype._handleHeaders = function handleHeaders(headers) {
 };
 
 Peer.prototype._handleReject = function handleReject(payload) {
-  var hash = utils.toHex(payload.data);
-  var entry = this._broadcast.map[hash];
+  var hash, entry;
 
   this.emit('reject', payload);
 
+  if (!payload.data)
+    return;
+
+  hash = utils.toHex(payload.data);
+  entry = this._broadcast.map[hash];
+
   if (!entry)
     return;
 
diff --git a/lib/bcoin/pool.js b/lib/bcoin/pool.js
index 8c576dcc..f2348b73 100644
--- a/lib/bcoin/pool.js
+++ b/lib/bcoin/pool.js
@@ -794,7 +794,7 @@ Pool.prototype._createPeer = function _createPeer(options) {
   });
 
   peer.on('reject', function(payload) {
-    var data = utils.revHex(utils.toHex(payload.data));
+    var data = payload.data ? utils.revHex(utils.toHex(payload.data)) : null;
 
     utils.debug(
       'Reject: msg=%s ccode=%s reason=%s data=%s',
diff --git a/lib/bcoin/script.js b/lib/bcoin/script.js
index 075f20bc..da327825 100644
--- a/lib/bcoin/script.js
+++ b/lib/bcoin/script.js
@@ -1295,9 +1295,9 @@ Script.createMultisig = function createMultisig(keys, m, n) {
   assert(m >= 1 && m <= n);
   assert(n >= 1 && n <= 15);
 
-  return new Script([m + 0x50].concat(
+  return new Script([opc[m]].concat(
     utils.sortKeys(keys),
-    [n + 0x50, opc.checkmultisig]
+    [opc[n], opc.checkmultisig]
   ));
 };
 
@@ -1357,8 +1357,8 @@ Script.prototype.isStandard = function isStandard() {
   var m, n;
 
   if (type === 'multisig') {
-    m = this.code[0] - 0x50;
-    n = this.code[this.code.length - 2] - 0x50;
+    m = Script.getSmall(this.code[0]);
+    n = Script.getSmall(this.code[this.code.length - 2]);
 
     if (n < 1 || n > 3)
       return false;
@@ -1526,26 +1526,16 @@ Script.prototype.isMultisig = function isMultisig(keys) {
   if (this.code[this.code.length - 1] !== opc.checkmultisig)
     return false;
 
-  n = this.code[this.code.length - 2];
+  n = Script.getSmall(this.code[this.code.length - 2]);
 
-  if (!(n >= opc['1'] && n <= opc['16']))
+  if (n == null)
     return false;
 
-  n -= 0x50;
+  m = Script.getSmall(this.code[0]);
 
-  // Bitcoind technically doesn't check for the
-  // 15 limit here. It just counts the sigops
-  // later.
-  if (!(n >= 1 && n <= 15))
+  if (m == null)
     return false;
 
-  m = this.code[0];
-
-  if (!(m >= opc['1'] && m <= opc['16']))
-    return false;
-
-  m -= 0x50;
-
   if (!(m >= 1 && m <= n))
     return false;
 
@@ -1634,7 +1624,8 @@ Script.prototype.isWitnessProgram = function isWitnessProgram() {
   if (!Buffer.isBuffer(this.code[1]))
     return false;
 
-  return this.code[0] >= opc['0'] && this.code[0] <= opc['16']
+  return (this.code[0] === opc['0']
+    || (this.code[0] >= opc['1'] && this.code[0] <= opc['16']))
     && this.code[1].length >= 2 && this.code[1].length <= 32;
 };
 
@@ -1644,15 +1635,15 @@ Script.prototype.getWitnessProgram = function getWitnessProgram() {
   if (!this.isWitnessProgram())
     return;
 
-  version = this.code[0];
+  version = Script.getSmall(this.code[0]);
   data = this.code[1];
 
   if (version > 0) {
     // No interpretation of script (anyone can spend)
     type = 'unknown';
-  } else if (version === opc['0'] && data.length === 20) {
+  } else if (version === 0 && data.length === 20) {
     type = 'witnesspubkeyhash';
-  } else if (version === opc['0'] && data.length === 32) {
+  } else if (version === 0 && data.length === 32) {
     type = 'witnessscripthash';
   } else {
     // Fail on bad version=0
@@ -1660,7 +1651,7 @@ Script.prototype.getWitnessProgram = function getWitnessProgram() {
   }
 
   return {
-    version: version === opc['0'] ? 0 : version - 0x50,
+    version: version,
     type: type,
     data: data
   };
@@ -2267,7 +2258,7 @@ Script.prototype.getArgs = function getArgs() {
 
   if (this.isMultisig()) {
     keys = this.code.slice(1, -2);
-    m = this.code[0] - 0x50;
+    m = Script.getSmall(this.code[0]);
     if (keys.length < 1 || m < 1)
       return -1;
     return m + 1;
@@ -2335,6 +2326,48 @@ Script.fromString = function fromString(code) {
   return new Script(code);
 };
 
+Script.getSmall = function getSmall(op) {
+  if (typeof op !== 'number')
+    return null;
+
+  if (op === opc['0'])
+    return 0;
+
+  if (op >= opc['1'] && op <= opc['16'])
+    return op - 0x50;
+
+  return null;
+};
+
+Script.fromSymbolic = function fromSymbolic(items) {
+  var code = new Array(items.length);
+  var i, op;
+
+  for (i = 0; i < items.length; i++) {
+    op = items[i];
+
+    if (Buffer.isBuffer(op)) {
+      code[i] = op;
+      continue;
+    }
+
+    if (+op === -1)
+      op = '1negate';
+    else if (+op === 0 || op === 'false')
+      op = 0;
+    else if (+op === 1 || op === 'true')
+      op = 1;
+    else if (+op >= 1 && +op <= 16)
+      op = +op;
+
+    code[i] = constants.opcodes[op];
+
+    assert(code[i] != null, 'Unknown opcode.');
+  }
+
+  return new Script(code);
+};
+
 Script.verify = function verify(input, witness, output, tx, i, flags) {
   var copy, res, raw, redeem, hadWitness;
   var stack = new Stack();