diff --git a/moderation/moderation.py b/moderation/moderation.py
index bea1616..8fe82b5 100644
--- a/moderation/moderation.py
+++ b/moderation/moderation.py
@@ -1794,7 +1794,7 @@ class Moderation(commands.Cog):
                     except OverflowError:
                         continue
                 else:
-                    duration = timedelta(seconds=0)
+                    duration = 'NULL'
 
                 if case['resolved']:
                     resolved = 1