diff --git a/mikazuki/process.py b/mikazuki/process.py
index bb292ad..3b6b138 100644
--- a/mikazuki/process.py
+++ b/mikazuki/process.py
@@ -21,7 +21,7 @@ def run_train(toml_path: str,
         "--config_file", toml_path,
     ]
     if multi_gpu:
-        args[3:2] = ["--multi_gpu", "--num_processes=2"]
+        args[3:3] = ["--multi_gpu", "--num_processes", "2"]
 
     customize_env = os.environ.copy()
     customize_env["ACCELERATE_DISABLE_RICH"] = "1"