diff --git a/server/ban_store.py b/server/ban_store.py
index 43fce70..98a7787 100644
--- a/server/ban_store.py
+++ b/server/ban_store.py
@@ -167,7 +167,10 @@ class BanStore:
         return entry
 
     def unban_ip(self, ip: str) -> bool:
-        normalized = self._normalize_ip(ip)
+        try:
+            normalized = self._normalize_ip(ip)
+        except ValueError:
+            return False
         with self._lock:
             if normalized not in self._bans:
                 return False