diff --git a/lurker/bot.py b/lurker/bot.py
index ae4d5bb..0e504f9 100644
--- a/lurker/bot.py
+++ b/lurker/bot.py
@@ -103,11 +103,11 @@ class Bot(discord.Client):
 
 def main(argv: typing.Sequence[str]):
     if len(argv) == 0:
-        print("Usage: lurker.py <token>")
+        print("Usage: lurker.py <token>", file=sys.stderr)
         return 1
 
     if not API_URL:
-        print("Missing `API_URL` environment variable.")
+        print("Missing `API_URL` environment variable.", file=sys.stderr)
         return 1
 
     Bot().run(argv[0])