diff --git a/lib/script/script.js b/lib/script/script.js
index 9eff54bf..47657aa7 100644
--- a/lib/script/script.js
+++ b/lib/script/script.js
@@ -1405,7 +1405,7 @@ Script.prototype.fromPubkey = function fromPubkey(key) {
   key = this.raw.slice(1, 1 + key.length);
 
   this.code.push(new Opcode(key.length, key));
-  this.code.push(new Opcode(opcodes.OP_CHECKSIG));
+  this.code.push(Opcode.fromOp(opcodes.OP_CHECKSIG));
 
   return this;
 };
@@ -1439,11 +1439,11 @@ Script.prototype.fromPubkeyhash = function fromPubkeyhash(hash) {
 
   hash = this.raw.slice(3, 23);
 
-  this.code.push(new Opcode(opcodes.OP_DUP));
-  this.code.push(new Opcode(opcodes.OP_HASH160));
+  this.code.push(Opcode.fromOp(opcodes.OP_DUP));
+  this.code.push(Opcode.fromOp(opcodes.OP_HASH160));
   this.code.push(new Opcode(0x14, hash));
-  this.code.push(new Opcode(opcodes.OP_EQUALVERIFY));
-  this.code.push(new Opcode(opcodes.OP_CHECKSIG));
+  this.code.push(Opcode.fromOp(opcodes.OP_EQUALVERIFY));
+  this.code.push(Opcode.fromOp(opcodes.OP_CHECKSIG));
 
   return this;
 };
@@ -1517,9 +1517,9 @@ Script.prototype.fromScripthash = function fromScripthash(hash) {
 
   hash = this.raw.slice(2, 22);
 
-  this.code.push(new Opcode(opcodes.OP_HASH160));
+  this.code.push(Opcode.fromOp(opcodes.OP_HASH160));
   this.code.push(new Opcode(0x14, hash));
-  this.code.push(new Opcode(opcodes.OP_EQUAL));
+  this.code.push(Opcode.fromOp(opcodes.OP_EQUAL));
 
   return this;
 };