diff --git a/runner.py b/runner.py
index 0d7f076..4901540 100644
--- a/runner.py
+++ b/runner.py
@@ -48,6 +48,8 @@ class Config:
 
 
 def poll() -> None:
+    global last_update
+
     params = {**config.params, "since": last_update}
 
     with requests.get(config.api_url, params=params) as resp: