diff --git a/app.py b/app.py
index c110acf..d0ffcc3 100644
--- a/app.py
+++ b/app.py
@@ -22,17 +22,23 @@ app = FastAPI(title="QL-1060N Stacked Barcode Printer")
 
 @lru_cache(maxsize=256)
 def make_code128(data: str) -> Image.Image:
-    writer_opts = {
-        "module_height": 15.0,
-        "module_width": 0.5,
-        "quiet_zone": 1.0,
-        "font_size": 10,
-        "text_distance": 1.0,
-    }
-    code = Code128(
-        data, writer=ImageWriter(), add_checksum=False, writer_options=writer_opts
+    # 1) Instantiate the barcode object (checksum auto-added for Code128)
+    code = Code128(data, writer=ImageWriter())
+
+    # 2) Render to a PIL.Image, passing any writer options and optional text override
+    pil_img = code.render(
+        writer_options={
+            "module_height": 15.0,  # bar height
+            "module_width": 0.5,  # bar thickness
+            "quiet_zone": 1.0,  # margin on each side
+            "font_size": 10,  # text size
+            "text_distance": 1.0,  # gap between bars and text
+            # you can also pass 'format': 'PNG' here if needed
+        },
+        text=data,  # explicitly draw your data string under the bars
     )
-    pil_img = code.render(writer_opts)  # returns RGB
+
+    # 3) Convert to 1-bit for your Brother QL workflow
     return pil_img.convert("1")