diff --git a/fluxer_api/src/api/guild/services/GuildModerationService.ts b/fluxer_api/src/api/guild/services/GuildModerationService.ts
index b511969d7..e6c325bae 100644
--- a/fluxer_api/src/api/guild/services/GuildModerationService.ts
+++ b/fluxer_api/src/api/guild/services/GuildModerationService.ts
@@ -8,6 +8,7 @@ import {MissingPermissionsError} from '@fluxer/errors/src/domains/core/MissingPe
 import {BannedFromGuildError} from '@fluxer/errors/src/domains/guild/BannedFromGuildError';
 import {IpBannedFromGuildError} from '@fluxer/errors/src/domains/guild/IpBannedFromGuildError';
 import {UnknownGuildMemberError} from '@fluxer/errors/src/domains/guild/UnknownGuildMemberError';
+import {UnknownUserError} from '@fluxer/errors/src/domains/user/UnknownUserError';
 import {isSameIpDecisionMatch} from '@fluxer/ip_utils/src/IpAddress';
 import type {GuildBanResponse} from '@fluxer/schema/src/domains/guild/GuildMemberSchemas';
 import type {IpInfoService} from '@pkgs/geoip/src/IpInfoService';
@@ -62,6 +63,10 @@ export class GuildModerationService {
 		});
 		if (!hasPermission) throw new MissingPermissionsError();
 		if (userId === targetId) throw new UnknownGuildMemberError();
+		const targetUser = await this.userRepository.findUnique(targetId);
+		if (!targetUser) {
+			throw new UnknownUserError();
+		}
 		const targetMember = await this.guildRepository.getMember(guildId, targetId);
 		if (targetMember) {
 			const canManage = await this.gatewayService.checkTargetMember({guildId, userId, targetUserId: targetId});
@@ -74,9 +79,8 @@ export class GuildModerationService {
 				days: deleteMessageDays,
 			});
 		}
-		const targetUser = await this.userRepository.findUnique(targetId);
-		const targetIp = targetUser?.lastActiveIp || null;
-		const targetEmail = targetUser?.email?.toLowerCase() || null;
+		const targetIp = targetUser.lastActiveIp || null;
+		const targetEmail = targetUser.email?.toLowerCase() || null;
 		let expiresAt: Date | null = null;
 		if (banDurationSeconds && banDurationSeconds > 0) {
 			expiresAt = new Date(Date.now() + banDurationSeconds * 1000);
diff --git a/fluxer_api/src/api/guild/tests/GuildMemberManagement.test.ts b/fluxer_api/src/api/guild/tests/GuildMemberManagement.test.ts
index 9ae3ae0ff..24f0ca9fc 100644
--- a/fluxer_api/src/api/guild/tests/GuildMemberManagement.test.ts
+++ b/fluxer_api/src/api/guild/tests/GuildMemberManagement.test.ts
@@ -186,6 +186,24 @@ describe('Guild Member Management', () => {
 			.expect(HTTP_STATUS.NO_CONTENT)
 			.execute();
 	});
+	test('should ban non-member from guild', async () => {
+		const {owner, guild} = await setupTestGuildWithMembers(harness, 1);
+		const nonMember = await createTestAccount(harness);
+		await createBuilder(harness, owner.token)
+			.put(`/guilds/${guild.id}/bans/${nonMember.userId}`)
+			.body({})
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+	});
+	test('should disallow banning nonexistent user from guild', async () => {
+		const {owner, guild} = await setupTestGuildWithMembers(harness, 1);
+		const nonExistentId = '1234567890123456789';
+		await createBuilder(harness, owner.token)
+			.put(`/guilds/${guild.id}/bans/${nonExistentId}`)
+			.body({})
+			.expect(HTTP_STATUS.NOT_FOUND)
+			.execute();
+	});
 	test('should fall back to audit log reason header when ban reason is omitted', async () => {
 		const {owner, members, guild} = await setupTestGuildWithMembers(harness, 1);
 		const member = members[0];