diff --git a/model/macfinder.py b/model/macfinder.py
index ab1be13791f0ffd91c092895cdf27cf3f6b1fb20..b38c4ea9e3b3c4dc10a0e147834320754503312e 100644
--- a/model/macfinder.py
+++ b/model/macfinder.py
@@ -16,6 +16,8 @@ if not settings.oui_lookup_disabled:
                 'https://standards-oui.ieee.org/oui36/oui36.txt']:
         ouis = requests.get(oui).text.split('\n')  # normal request, not with fastapi Request Object
         last_hex = ''
+        if len(ouis) == 0:
+            raise ValueError(f'Empty OUI-DB from {oui}!')
         for line in ouis:
             if '(hex)' not in line:
                 if '(base 16)' in line: