diff --git a/lib/script/script.js b/lib/script/script.js
index 176efdb35..24c31c9d4 100644
--- a/lib/script/script.js
+++ b/lib/script/script.js
@@ -228,7 +228,21 @@ Script.prototype._chunkToString = function(chunk, type) {
   if (!chunk.buf) {
     // no data chunk
     if (typeof Opcode.reverseMap[opcodenum] !== 'undefined') {
-      str = str + ' ' + Opcode(opcodenum).toString();
+      if (asm) {
+        // A few cases where the opcode name differs from reverseMap
+        // aside from 1 to 16 data pushes.
+        if (opcodenum === 0) {
+          // OP_0 -> 0
+          str = str + ' 0';
+        } else if(opcodenum === 79) {
+          // OP_1NEGATE -> 1
+          str = str + ' -1';
+        } else {
+          str = str + ' ' + Opcode(opcodenum).toString();
+        }
+      } else {
+        str = str + ' ' + Opcode(opcodenum).toString();
+      }
     } else {
       var numstr = opcodenum.toString(16);
       if (numstr.length % 2 !== 0) {
@@ -242,7 +256,7 @@ Script.prototype._chunkToString = function(chunk, type) {
     }
   } else {
     // data chunk
-    if (opcodenum === Opcode.OP_PUSHDATA1 ||
+    if (!asm && opcodenum === Opcode.OP_PUSHDATA1 ||
       opcodenum === Opcode.OP_PUSHDATA2 ||
       opcodenum === Opcode.OP_PUSHDATA4) {
       str = str + ' ' + Opcode(opcodenum).toString();
diff --git a/test/script/script.js b/test/script/script.js
index 2434b7b63..1fb5053db 100644
--- a/test/script/script.js
+++ b/test/script/script.js
@@ -209,6 +209,18 @@ describe('Script', function() {
       script.toASM().should.equal('OP_DUP OP_HASH160 f4c03610e60ad15100929cc23da2f3a799af1725 OP_EQUALVERIFY OP_CHECKSIG');
     });
 
+    it('should output this known script with pushdata1 opcode as ASM', function() {
+      // network: livenet
+      // txid: dd6fabd2d879be7b8394ad170ff908e9a36b5d5d0b394508df0cca36d2931589
+      var script = Script.fromHex('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');
+      script.toASM().should.equal('0 3045022100beb1d83771c04faaeb40bded4f031ed0e0730aaab77cf70102ecd05734a1762002206f168fb00f3b9d7c04b8c78e1fc11e81b9caa49885a904bf22780a7e14a8373101 3045022100a319839e37828bf164ff45de34a3fe22d542ebc8297c5d87dbc56fc3068ff9d5022077081a877b6e7f104d8a2fe0985bf2eb7de2e08edbac9499fc3710a353f6546101 522103a70ae7bde64333461fb88aaafe12ad6c67ca17c8213642469ae191e0aabc7251210344a62338c8ddf138771516d38187146242db50853aa588bcb10a5e49c86421a52102b52a1aed304c4d6cedcf82911f90ca6e1ffed0a5b8f7f19c68213d6fcbde677e53ae');
+    });
+
+    it('should OP_1NEGATE opcode as -1 with ASM', function() {
+      var script = Script.fromString('OP_1NEGATE');
+      script.toASM().should.equal('-1');
+    });
+
   });
 
   describe('toHex', function() {