diff --git a/src/Discord.Net.Core/Entities/Guilds/IGuild.cs b/src/Discord.Net.Core/Entities/Guilds/IGuild.cs
index 6c7b73370..8da731855 100644
--- a/src/Discord.Net.Core/Entities/Guilds/IGuild.cs
+++ b/src/Discord.Net.Core/Entities/Guilds/IGuild.cs
@@ -65,8 +65,10 @@ namespace Discord
/// Gets a collection of all users banned on this guild.
Task> GetBansAsync(RequestOptions options = null);
/// Bans the provided user from this guild and optionally prunes their recent messages.
+ /// The number of days to remove messages from this user for - must be between [0, 7]
Task AddBanAsync(IUser user, int pruneDays = 0, RequestOptions options = null);
/// Bans the provided user id from this guild and optionally prunes their recent messages.
+ /// The number of days to remove messages from this user for - must be between [0, 7]
Task AddBanAsync(ulong userId, int pruneDays = 0, RequestOptions options = null);
/// Unbans the provided user if it is currently banned.
Task RemoveBanAsync(IUser user, RequestOptions options = null);
diff --git a/src/Discord.Net.Rest/DiscordRestApiClient.cs b/src/Discord.Net.Rest/DiscordRestApiClient.cs
index c57d15645..a632e5d42 100644
--- a/src/Discord.Net.Rest/DiscordRestApiClient.cs
+++ b/src/Discord.Net.Rest/DiscordRestApiClient.cs
@@ -798,7 +798,8 @@ namespace Discord.API
Preconditions.NotEqual(guildId, 0, nameof(guildId));
Preconditions.NotEqual(userId, 0, nameof(userId));
Preconditions.NotNull(args, nameof(args));
- Preconditions.AtLeast(args.DeleteMessageDays, 0, nameof(args.DeleteMessageDays));
+ Preconditions.AtLeast(args.DeleteMessageDays, 0, nameof(args.DeleteMessageDays), "Prune length must be within [0, 7]");
+ Preconditions.AtMost(args.DeleteMessageDays, 7, nameof(args.DeleteMessageDays), "Prune length must be within [0, 7]");
options = RequestOptions.CreateOrClone(options);
var ids = new BucketIds(guildId: guildId);