diff --git a/js8080simBundle.js b/js8080simBundle.js
index d53b63d..f1e9a25 100644
--- a/js8080simBundle.js
+++ b/js8080simBundle.js
@@ -387,7 +387,7 @@ class Assembler {
       }
       case 'sta': {
         this._expectArgsCount(sl, 1);
-        let num = this._argImmOrLabel(sl, sl.args[1], curAddr);
+        let num = this._argImmOrLabel(sl, sl.args[0], curAddr);
         // 16-bit immediates encoded litte-endian.
         return [0b00110010, num & 0xff, (num >> 8) & 0xff];
       }
diff --git a/package.json b/package.json
index e155ffd..1caec00 100644
--- a/package.json
+++ b/package.json
@@ -18,5 +18,8 @@
   "homepage": "https://github.com/eliben/js-8080-sim#readme",
   "devDependencies": {
     "mocha": "^8.4.0"
+  },
+  "dependencies": {
+    "browserify": "^17.0.0"
   }
 }