diff --git a/routes/api/export/gallery/zip/[gid].ts b/routes/api/export/gallery/zip/[gid].ts
index ed7e00c..6b8dfcf 100644
--- a/routes/api/export/gallery/zip/[gid].ts
+++ b/routes/api/export/gallery/zip/[gid].ts
@@ -1,7 +1,7 @@
 import { Handlers } from "$fresh/server.ts";
 import { get_task_manager } from "../../../../../server.ts";
 import { get_export_zip_response } from "../../../../../server/export_zip.ts";
-import { parse_bool } from "../../../../../server/parse_form.ts";
+import { parse_bool, parse_int } from "../../../../../server/parse_form.ts";
 import { ExportZipConfig } from "../../../../../tasks/export_zip.ts";
 
 export const handler: Handlers = {
@@ -13,6 +13,7 @@ export const handler: Handlers = {
         const params = new URL(req.url).searchParams;
         const cfg: ExportZipConfig = {};
         cfg.jpn_title = await parse_bool(params.get("jpn_title"), false);
+        cfg.max_length = await parse_int(params.get("max_length"), 0);
         const m = get_task_manager();
         return get_export_zip_response(gid, m.db, cfg);
     },
diff --git a/server/export_zip.ts b/server/export_zip.ts
index 1d403ff..3153ab1 100644
--- a/server/export_zip.ts
+++ b/server/export_zip.ts
@@ -1,7 +1,7 @@
 import { Uint8ArrayReader, ZipWriter } from "zipjs/index.js";
 import { EhDb, PMeta } from "../db.ts";
 import { ExportZipConfig } from "../tasks/export_zip.ts";
-import { addZero, configureZipJs } from "../utils.ts";
+import { addZero, configureZipJs, limitFilename } from "../utils.ts";
 
 export function get_export_zip_response(
     gid: number,
@@ -47,12 +47,13 @@ export function get_export_zip_response(
     let closed = false;
     const signalc = new AbortController();
     const signal = signalc.signal;
+    const maxLength = cfg.max_length || 0;
     const download_task = async (p: PMeta) => {
         const f = db.get_files(p.token);
         if (f.length) {
             const r = await Deno.readFile(f[0].path, { signal });
             await zip_writer.add(
-                `${addZero(p.index, l)}_${p.name}`,
+                limitFilename(`${addZero(p.index, l)}_${p.name}`, maxLength),
                 new Uint8ArrayReader(r),
                 { signal },
             );
diff --git a/server/parse_form.ts b/server/parse_form.ts
index cb96ee0..9990120 100644
--- a/server/parse_form.ts
+++ b/server/parse_form.ts
@@ -12,3 +12,14 @@ export async function parse_bool<T extends boolean | null>(
         return n !== 0;
     }
 }
+
+export async function parse_int<T extends number | null>(
+    value: FormDataEntryValue | null,
+    def: T,
+): Promise<number | T> {
+    if (value === null) return def;
+    const v = typeof value === "string" ? value : await value.text();
+    const n = parseInt(v);
+    if (isNaN(n)) return def;
+    return n;
+}
diff --git a/server/parse_form_test.ts b/server/parse_form_test.ts
index f462f35..3c9331c 100644
--- a/server/parse_form_test.ts
+++ b/server/parse_form_test.ts
@@ -1,5 +1,5 @@
 import { assertEquals } from "std/testing/asserts.ts";
-import { parse_bool } from "./parse_form.ts";
+import { parse_bool, parse_int } from "./parse_form.ts";
 
 Deno.test("parse_bool_test", async () => {
     const f = new FormData();
@@ -15,3 +15,15 @@ Deno.test("parse_bool_test", async () => {
     f.append("e", "tRUE", "a.png");
     assertEquals(await parse_bool(f.get("e"), null), true);
 });
+
+Deno.test("parse_int_test", async () => {
+    const f = new FormData();
+    f.append("a", "d");
+    assertEquals(await parse_int(f.get("a"), null), null);
+    assertEquals(await parse_int(f.get("a"), 1), 1);
+    f.append("c", "1");
+    assertEquals(await parse_int(f.get("c"), null), 1);
+    assertEquals(await parse_int(f.get("c"), 2), 1);
+    f.append("d", "-1");
+    assertEquals(await parse_int(f.get("d"), null), -1);
+});
diff --git a/tasks/export_zip.ts b/tasks/export_zip.ts
index 0e95dc7..4bcc5d1 100644
--- a/tasks/export_zip.ts
+++ b/tasks/export_zip.ts
@@ -6,6 +6,7 @@ import {
     asyncForEach,
     configureZipJs,
     filterFilename,
+    limitFilename,
 } from "../utils.ts";
 import { Config } from "../config.ts";
 import { Task, TaskExportZipProgress, TaskType } from "../task.ts";
@@ -14,6 +15,7 @@ import { TaskManager } from "../task_manager.ts";
 export type ExportZipConfig = {
     output?: string;
     jpn_title?: boolean;
+    max_length?: number;
 };
 
 export const DEFAULT_EXPORT_ZIP_CONFIG: ExportZipConfig = {};
@@ -47,6 +49,7 @@ export async function export_zip(
     const output = ecfg.output === undefined
         ? join(cfg.base, filterFilename(title + ".zip"))
         : ecfg.output;
+    const maxLength = ecfg.max_length || 0;
     const f = await Deno.open(output, {
         create: true,
         write: true,
@@ -66,7 +69,10 @@ export async function export_zip(
                 if (f.length) {
                     const r = await Deno.readFile(f[0].path, { signal });
                     await z.add(
-                        `${addZero(p.index, l)}_${p.name}`,
+                        limitFilename(
+                            `${addZero(p.index, l)}_${p.name}`,
+                            maxLength,
+                        ),
                         new Uint8ArrayReader(r),
                         { signal },
                     );
diff --git a/utils.ts b/utils.ts
index c454dcb..51b1d49 100644
--- a/utils.ts
+++ b/utils.ts
@@ -141,8 +141,13 @@ export function filterFilename(p: string, maxLength = 256) {
     } else if (Deno.build.os == "linux") {
         p = p.replace(/[!\$\"]/g, "_");
     }
-    if (p.length > maxLength) {
+    return limitFilename(p, maxLength);
+}
+
+export function limitFilename(p: string, maxLength: number) {
+    if (maxLength > 0 && p.length > maxLength) {
         const ext = extname(p);
+        if (maxLength < ext.length) return ext;
         return p.slice(0, maxLength - ext.length) + ext;
     }
     return p;
diff --git a/utils_test.ts b/utils_test.ts
index f1b0241..d175247 100644
--- a/utils_test.ts
+++ b/utils_test.ts
@@ -82,6 +82,7 @@ Deno.test("filterFilename_test", () => {
     if (Deno.build.os == "windows") {
         assertEquals(filterFilename("d|?ad.ts"), "d__ad.ts");
     }
+    assertEquals(filterFilename("t|.ts", 0), "t_.ts");
 });
 
 Deno.test("add_suffix_to_path_test", () => {