diff --git a/scripts/quantize_nvfp4.py b/scripts/quantize_nvfp4.py
index 4532a73..37a520f 100644
--- a/scripts/quantize_nvfp4.py
+++ b/scripts/quantize_nvfp4.py
@@ -227,6 +227,12 @@ def run_calibration(model_path, export_dir, calib_save_path, amax_snapshot_path,
     args = parse_args()
     sys.argv = saved_argv
 
+    # Apply the same post-parse conversions that hf_ptq's __main__ block does
+    # (these normally run between parse_args() and main() in the original script,
+    # but since we call main() directly, we have to do them ourselves)
+    args.dataset = args.dataset.split(",") if isinstance(args.dataset, str) else args.dataset
+    args.calib_size = [int(num_sample) for num_sample in args.calib_size.split(",")]
+
     # ── Post-calibration hook ──
     # We monkey-patch export_quantized to add our defensive saves before export.
     import hf_ptq