diff --git a/hwe/ts/battle_simulator.ts b/hwe/ts/battle_simulator.ts
index 6de0eb4f..920b7ce3 100644
--- a/hwe/ts/battle_simulator.ts
+++ b/hwe/ts/battle_simulator.ts
@@ -2,7 +2,7 @@ import $ from 'jquery';
 import 'bootstrap';
 import { DateTime } from 'luxon';
 import download from 'downloadjs';
-import { unwrap } from './util';
+import { unwrap } from "./util/unwrap";
 import { isInteger } from 'lodash';
 import { combineArray, errUnknown, getNpcColor, isBrightColor, numberWithCommas } from './common_legacy';
 import { unwrap_any } from './util/unwrap_any';
diff --git a/hwe/ts/chiefCenter.ts b/hwe/ts/chiefCenter.ts
index 6cd78328..543d4196 100644
--- a/hwe/ts/chiefCenter.ts
+++ b/hwe/ts/chiefCenter.ts
@@ -4,7 +4,7 @@ import { range } from 'lodash';
 import { DateTime } from 'luxon';
 import { errUnknown, getNpcColor } from './common_legacy';
 import { InvalidResponse } from './defs';
-import { unwrap } from './util';
+import { unwrap } from "./util/unwrap";
 import { convertFormData } from './util/convertFormData';
 import { unwrap_any } from "./util/unwrap_any";
 
diff --git a/hwe/ts/common_legacy.ts b/hwe/ts/common_legacy.ts
index d03ffe21..3fbc72e7 100644
--- a/hwe/ts/common_legacy.ts
+++ b/hwe/ts/common_legacy.ts
@@ -1,4 +1,4 @@
-import { unwrap } from "./util";
+import { unwrap } from "./util/unwrap";
 
 import jQuery from "jquery";
 import 'bootstrap';
@@ -8,7 +8,7 @@ import axios from "axios";
 axios.defaults.headers.common['X-Requested-With'] = 'XMLHttpRequest';
 //TODO: X-Requested-With 믿지 말자.
 
-/** 
+/**
  * <>& 등을 html에서도 그대로 보이도록 escape주는 함수
  * @see https://stackoverflow.com/questions/24816/escaping-html-strings-with-jquery
  */
@@ -121,7 +121,7 @@ export function convertSet<K extends string | number>(arr: ArrayLike<K>): Record
 }
 
 
-/** 
+/**
  * {0}, {1}, {2}형태로 포맷해주는 함수
  */
 
@@ -199,8 +199,8 @@ export function linkifyStrWithOpt(text: string): string {
 /**
  * 단순한 Template 함수.  <%변수명%>으로 template 가능
  * @see  https://github.com/krasimir/absurd/blob/master/lib/processors/html/helpers/TemplateEngine.js
- * @param {string} html 
- * @param {object} options 
+ * @param {string} html
+ * @param {object} options
  * @returns {string}
  */
 export function TemplateEngine(html: string, options: Record<string | number, unknown> = {}): string {
@@ -332,7 +332,7 @@ export function nl2br(text: string): string {
     return text.replace(/\n/g, "<br>");
 }
 /*
-function br2nl (text) {   
+function br2nl (text) {
     return text.replace(/<\s*\/?br\s*[\/]?>/gi, '\n');
 }
 */
diff --git a/hwe/ts/ext.plugin_troop.ts b/hwe/ts/ext.plugin_troop.ts
index e514bc42..529537ae 100644
--- a/hwe/ts/ext.plugin_troop.ts
+++ b/hwe/ts/ext.plugin_troop.ts
@@ -1,5 +1,6 @@
 import axios from "axios";
-import { RuntimeError, unwrap } from "./util";
+import { unwrap } from "./util/unwrap";
+import { RuntimeError } from "./util/RuntimeError";
 
 declare global {
     interface Window {
@@ -46,7 +47,7 @@ export function launchTroopPlugin($: JQueryStatic): void {
         const rawData = response.data;
 
         try {
-            const $html = $(rawData); 
+            const $html = $(rawData);
 
             const tmpUsers: JQuery<HTMLElement> = (() => {
                 let tmpUsers = undefined;
diff --git a/hwe/ts/inheritPoint.ts b/hwe/ts/inheritPoint.ts
index ae10b6dd..f63b1713 100644
--- a/hwe/ts/inheritPoint.ts
+++ b/hwe/ts/inheritPoint.ts
@@ -1,9 +1,9 @@
 import "../scss/inheritPoint.scss";
 
 import { sum } from "lodash";
-import { unwrap } from "./util";
+import { unwrap } from "./util/unwrap";
 declare global {
-    interface Window { 
+    interface Window {
         formStart: ()=>void;
         items: {[name: string]:number};
         helpText: {[name: string]:string};
diff --git a/hwe/ts/map.ts b/hwe/ts/map.ts
index c7e2800f..a11bafd9 100644
--- a/hwe/ts/map.ts
+++ b/hwe/ts/map.ts
@@ -3,7 +3,7 @@ import $ from 'jquery';
 import { extend, isNumber } from 'lodash';
 import { convColorValue, convertDictById, convertSet } from './common_legacy';
 import { InvalidResponse } from './defs';
-import { unwrap } from './util';
+import { unwrap } from "./util/unwrap";
 import { convertFormData } from './util/convertFormData';
 
 declare const serverNick: string;
diff --git a/hwe/ts/processing.ts b/hwe/ts/processing.ts
index c960129b..424176b7 100644
--- a/hwe/ts/processing.ts
+++ b/hwe/ts/processing.ts
@@ -7,7 +7,7 @@ import { convertFormData } from './util/convertFormData';
 import { InvalidResponse } from './defs';
 import { unwrap_any } from './util/unwrap_any';
 import { DataFormat, IdTextPair, OptionData } from 'select2';
-import { unwrap } from './util';
+import { unwrap } from "./util/unwrap";
 
 declare const isChiefTurn: boolean;
 declare global {
diff --git a/hwe/ts/util.ts b/hwe/ts/util.ts
deleted file mode 100644
index f1b3bc07..00000000
--- a/hwe/ts/util.ts
+++ /dev/null
@@ -1,35 +0,0 @@
-type ErrType<T> = { new(msg?: string): T }
-export type Nullable<T> = T | null | undefined
-
-export class RuntimeError extends Error {
-    public name = 'RuntimeError';
-    constructor(public message: string = '') {
-        super(message);
-    }
-    toString(): string {
-        if (this.message) {
-            return this.name + ': ' + this.message;
-        }
-        else {
-            return this.name;
-        }
-    }
-}
-
-export class NotNullExpected extends RuntimeError {
-    public name = 'NotNullExpected';
-}
-
-export function unwrap<T>(result: Nullable<T>): T {
-    if (result === null || result === undefined) {
-        throw new NotNullExpected();
-    }
-    return result;
-}
-
-export function unwrap_err<T, ErrT extends Error>(result: Nullable<T>, errType: ErrType<ErrT>, errMsg?: string): T {
-    if (result === null || result === undefined) {
-        throw new errType(errMsg);
-    }
-    return result;
-}
\ No newline at end of file
diff --git a/hwe/ts/util/NotNullExpected.ts b/hwe/ts/util/NotNullExpected.ts
new file mode 100644
index 00000000..1ea17d1b
--- /dev/null
+++ b/hwe/ts/util/NotNullExpected.ts
@@ -0,0 +1,4 @@
+
+export class NotNullExpected extends TypeError {
+    public name = 'NotNullExpected';
+}
diff --git a/hwe/ts/util/Nullable.ts b/hwe/ts/util/Nullable.ts
new file mode 100644
index 00000000..164a7056
--- /dev/null
+++ b/hwe/ts/util/Nullable.ts
@@ -0,0 +1 @@
+export type Nullable<T> = T | null | undefined;
diff --git a/hwe/ts/util/RuntimeError.ts b/hwe/ts/util/RuntimeError.ts
new file mode 100644
index 00000000..59920289
--- /dev/null
+++ b/hwe/ts/util/RuntimeError.ts
@@ -0,0 +1,14 @@
+export class RuntimeError extends Error {
+    public name = 'RuntimeError';
+    constructor(public message: string = '') {
+        super(message);
+    }
+    toString(): string {
+        if (this.message) {
+            return this.name + ': ' + this.message;
+        }
+        else {
+            return this.name;
+        }
+    }
+}
diff --git a/hwe/ts/util/unwrap.ts b/hwe/ts/util/unwrap.ts
new file mode 100644
index 00000000..68c1936f
--- /dev/null
+++ b/hwe/ts/util/unwrap.ts
@@ -0,0 +1,9 @@
+import { Nullable } from "./Nullable";
+import { NotNullExpected } from "./NotNullExpected";
+
+export function unwrap<T>(result: Nullable<T>): T {
+    if (result === null || result === undefined) {
+        throw new NotNullExpected();
+    }
+    return result;
+}
diff --git a/hwe/ts/util/unwrap_any.ts b/hwe/ts/util/unwrap_any.ts
index ece83c39..70d343c8 100644
--- a/hwe/ts/util/unwrap_any.ts
+++ b/hwe/ts/util/unwrap_any.ts
@@ -1,4 +1,5 @@
-import { Nullable, NotNullExpected } from "../util";
+import { Nullable } from "./Nullable";
+import { NotNullExpected } from "./NotNullExpected";
 
 
 export function unwrap_any<T>(result: Nullable<unknown>): T {
diff --git a/hwe/ts/util/unwrap_err.ts b/hwe/ts/util/unwrap_err.ts
new file mode 100644
index 00000000..eee98384
--- /dev/null
+++ b/hwe/ts/util/unwrap_err.ts
@@ -0,0 +1,10 @@
+import { Nullable } from "./Nullable";
+
+type ErrType<T> = { new(msg?: string): T }
+
+export function unwrap_err<T, ErrT extends Error>(result: Nullable<T>, errType: ErrType<ErrT>, errMsg?: string): T {
+    if (result === null || result === undefined) {
+        throw new errType(errMsg);
+    }
+    return result;
+}
diff --git a/ts/user_info.ts b/ts/user_info.ts
index bb718633..352440f6 100644
--- a/ts/user_info.ts
+++ b/ts/user_info.ts
@@ -7,7 +7,7 @@ import { DATE_TIME_FORMAT, getDateTimeNow } from "../hwe/ts/util/getDateTimeNow"
 import { sha512 } from "js-sha512";
 import { convertFormData } from "../hwe/ts/util/convertFormData";
 import { InvalidResponse } from "../hwe/ts/defs";
-import { unwrap } from "./util";
+import { unwrap } from "../hwe/ts/util/unwrap";
 
 type ResultUserInfo = {
     result: true,
diff --git a/ts/util.ts b/ts/util.ts
deleted file mode 100644
index 99a04ab5..00000000
--- a/ts/util.ts
+++ /dev/null
@@ -1,35 +0,0 @@
-type ErrType<T> = { new(msg?: string): T }
-type Nullable<T> = T | null | undefined
-
-export class RuntimeError extends Error {
-    public name = 'RuntimeError';
-    constructor(public message: string = '') {
-        super(message);
-    }
-    toString(): string {
-        if (this.message) {
-            return this.name + ': ' + this.message;
-        }
-        else {
-            return this.name;
-        }
-    }
-}
-
-export class NotNullExpected extends RuntimeError {
-    public name = 'NotNullExpected';
-}
-
-export function unwrap<T>(result: Nullable<T>): T {
-    if (result === null || result === undefined) {
-        throw new NotNullExpected();
-    }
-    return result;
-}
-
-export function unwrap_err<T, ErrT extends Error>(result: Nullable<T>, errType: ErrType<ErrT>, errMsg?: string): T {
-    if (result === null || result === undefined) {
-        throw new errType(errMsg);
-    }
-    return result;
-}
\ No newline at end of file