diff --git a/fastchat/serve/monitor/copilot_arena.py b/fastchat/serve/monitor/copilot_arena.py
index 80786e341..369115856 100644
--- a/fastchat/serve/monitor/copilot_arena.py
+++ b/fastchat/serve/monitor/copilot_arena.py
@@ -7,12 +7,6 @@
 
 copilot_arena_leaderboard_url = os.getenv("COPILOT_ARENA_LEADERBOARD_URL")
 
-if not copilot_arena_leaderboard_url:
-    raise ValueError(
-        "COPILOT_ARENA_LEADERBOARD_URL environment variable is not set. "
-        "Please configure it to a valid URL."
-    )
-
 
 def process_copilot_arena_leaderboard(leaderboard):
     leaderboard = leaderboard.copy().loc[leaderboard["visibility"] == "public"]
@@ -41,9 +35,6 @@ def process_copilot_arena_leaderboard(leaderboard):
 
 
 def build_copilot_arena_tab():
-    if copilot_arena_leaderboard_url is None:
-        print("Copilot Arena Leaderboard URL is not set. Skipping this leaderboard.")
-        return
     response = requests.get(copilot_arena_leaderboard_url)
     if response.status_code == 200:
         leaderboard = pd.DataFrame(response.json()["elo_data"])
diff --git a/fastchat/serve/monitor/monitor.py b/fastchat/serve/monitor/monitor.py
index 9f7e0dd08..f21cf4a58 100644
--- a/fastchat/serve/monitor/monitor.py
+++ b/fastchat/serve/monitor/monitor.py
@@ -1035,11 +1035,17 @@ def build_leaderboard_tab(
                     elo_results_text, model_table_df, model_to_score
                 )
             try:
-                with gr.Tab("Copilot Arena Leaderboard", id=5):
-                    from fastchat.serve.monitor.copilot_arena import (
-                        build_copilot_arena_tab,
-                    )
+                from fastchat.serve.monitor.copilot_arena import (
+                    build_copilot_arena_tab,
+                    copilot_arena_leaderboard_url,
+                )
 
+                if not copilot_arena_leaderboard_url:
+                    raise ValueError(
+                        "COPILOT_ARENA_LEADERBOARD_URL environment variable is not set. "
+                        "Please configure it to a valid URL."
+                    )
+                with gr.Tab("Copilot Arena Leaderboard", id=5):
                     build_copilot_arena_tab()
             except Exception as e:
                 print(f"Unable to build Copilot Arena's Leaderboard. Error: {e}")