diff --git a/lib/bcoin/script.js b/lib/bcoin/script.js
index 725be882..21aaef4e 100644
--- a/lib/bcoin/script.js
+++ b/lib/bcoin/script.js
@@ -2548,12 +2548,12 @@ Script.prototype.fromMultisig = function fromMultisig(m, n, keys) {
 
   keys = utils.sortKeys(keys);
 
-  this.push(m + 0x50);
+  this.push(Opcode.fromSmall(m));
 
   for (i = 0; i < keys.length; i++)
     this.push(keys[i]);
 
-  this.push(n + 0x50);
+  this.push(Opcode.fromSmall(n));
   this.push(opcodes.OP_CHECKMULTISIG);
 
   this.compile();
@@ -2633,7 +2633,7 @@ Script.fromNulldata = function fromNulldata(flags) {
 Script.prototype.fromProgram = function fromProgram(version, data) {
   assert(utils.isNumber(version) && version >= 0 && version <= 16);
   assert(Buffer.isBuffer(data) && data.length >= 2 && data.length <= 40);
-  this.push(version === 0 ? 0 : version + 0x50);
+  this.push(Opcode.fromSmall(version));
   this.push(data);
   this.compile();
   return this;
@@ -2850,7 +2850,7 @@ Script.prototype.isPubkey = function isPubkey(minimal) {
  */
 
 Script.prototype.isPubkeyhash = function isPubkeyhash(minimal) {
-  if (!minimal) {
+  if (minimal) {
     return this.raw.length === 25
       && this.raw[0] === opcodes.OP_DUP
       && this.raw[1] === opcodes.OP_HASH160