diff --git a/moderation/moderation.py b/moderation/moderation.py
index f6b3919..3b9d979 100644
--- a/moderation/moderation.py
+++ b/moderation/moderation.py
@@ -1490,7 +1490,7 @@ class Moderation(commands.Cog):
         blacklist_roles.append(
             {
             'role': role.id,
-            'duration': parsed_time
+            'duration': str(parsed_time)
             }
         )
         await self.config.guild(ctx.guild).blacklist_roles.set(blacklist_roles)