diff --git a/realhf/system/generation_server.py b/realhf/system/generation_server.py
index 96c043d..9bf39dc 100644
--- a/realhf/system/generation_server.py
+++ b/realhf/system/generation_server.py
@@ -41,11 +41,7 @@ def execute_shell_command(command: str) -> subprocess.Popen:
     )
 
 
-def launch_server_cmd(command: str, port: int = 30000):
-    """
-    Launch the server using the given command.
-    If no port is specified, a free port is reserved.
-    """
+def apply_sglang_path():
     p = Path(os.path.dirname(__file__))
     patch_path = str(
         p.parent.parent
@@ -72,6 +68,15 @@ def launch_server_cmd(command: str, port: int = 30000):
         )
         proc.wait()
         logger.info(f"Applied SGLang patch at {target_path}")
+
+
+def launch_server_cmd(command: str, port: int = 30000):
+    """
+    Launch the server using the given command.
+    If no port is specified, a free port is reserved.
+    """
+    if not ray.is_initialized():
+        apply_sglang_path()
     assert port is not None
     full_command = f"{command} --port {port}"
     process = execute_shell_command(full_command)