diff --git a/assembler.js b/assembler.js
index 63f9cc4..941ba99 100644
--- a/assembler.js
+++ b/assembler.js
@@ -153,7 +153,7 @@ function handleConstantDefinitions(op, arg, IP, constants) {
  * @param {SourceLineInfo} line
  * @returns {Object}
  **/
-function assembleMnemonicsWithOptionalArgs(line, assemblerState) {
+function assembleMnemonicsWithOptionalArgs(line) {
   if (mnemonicsWithOptionalArgs.indexOf(line.operation) < 0) {
     console.error(`Missing opcode for line ${line.number}: ${line.source}`);
     throw new Error("Missing opcode");
@@ -206,7 +206,8 @@ function decodeInstructions(source) {
 
   // Decode line by line...
   for (let i = 0; i < lines.length; i++) {
-    let line = lines[0];
+    let line = lines[i];
+    console.log(line);
     if (line.type === 'code') {
       const op = line.operation;
       const arg = null;
@@ -246,6 +247,9 @@ function decodeInstructions(source) {
       /** @typedef {'direct'|'indirect'} AddressingMode **/
       let addressingMode = 'direct';
 
+      // Now that it can't be a label or a constant, normalize the opcode
+      line.operation = line.operation.toLowerCase();
+
 
       // Operands - Handle references to labels
       if (arg !== null && arg.startsWith(ASM_LABEL_PREFIX)) {