diff --git a/tests/test_readme.py b/tests/test_readme.py
index 131d28de24..572fec7497 100644
--- a/tests/test_readme.py
+++ b/tests/test_readme.py
@@ -175,7 +175,7 @@ def test_continue_pretrain_model(tmp_path):
 def test_serve():
     CHECKPOINT_DIR = str("checkpoints" / REPO_ID)
     run_command = [
-        "litgpt", "serve", "--devices","0", str(CHECKPOINT_DIR)
+        "litgpt", "serve", "--devices 0", str(CHECKPOINT_DIR)
     ]
 
     process = None