diff --git a/src/client/components/post-form.vue b/src/client/components/post-form.vue
index a67f3ed10a6dc36b7e5b0e332744135b5c57d1c6..ce79f34d6227c3827351bf75c1741c4661bd4f63 100644
--- a/src/client/components/post-form.vue
+++ b/src/client/components/post-form.vue
@@ -61,7 +61,7 @@ import XNotePreview from './note-preview.vue';
 import * as mfm from 'mfm-js';
 import { host, url } from '@client/config';
 import { erase, unique } from '../../prelude/array';
-import extractMentions from '@/misc/extract-mentions';
+import { extractMentions } from '@/misc/extract-mentions';
 import getAcct from '@/misc/acct/render';
 import { formatTimeString } from '@/misc/format-time-string';
 import { Autocomplete } from '@client/scripts/autocomplete';
diff --git a/src/client/ui/chat/post-form.vue b/src/client/ui/chat/post-form.vue
index bdf18cf2901d435a10e78dc477b183cbb67d043e..a9413ea8bc83a05edcccd13e80f23c9acf3de10e 100644
--- a/src/client/ui/chat/post-form.vue
+++ b/src/client/ui/chat/post-form.vue
@@ -56,7 +56,7 @@ import { toASCII } from 'punycode/';
 import * as mfm from 'mfm-js';
 import { host, url } from '@client/config';
 import { erase, unique } from '../../../prelude/array';
-import extractMentions from '@/misc/extract-mentions';
+import { extractMentions } from '@/misc/extract-mentions';
 import getAcct from '@/misc/acct/render';
 import { formatTimeString } from '@/misc/format-time-string';
 import { Autocomplete } from '@client/scripts/autocomplete';
diff --git a/src/misc/extract-custom-emojis-from-mfm.ts b/src/misc/extract-custom-emojis-from-mfm.ts
index f1477a79f08d9f135ac9111d86d1f4d0f49cda22..ef2cb1fd6c27c7a2ce817443799bbfdb66a274a2 100644
--- a/src/misc/extract-custom-emojis-from-mfm.ts
+++ b/src/misc/extract-custom-emojis-from-mfm.ts
@@ -2,17 +2,13 @@ import * as mfm from 'mfm-js';
 import { unique } from '@/prelude/array';
 
 export function extractCustomEmojisFromMfm(nodes: mfm.MfmNode[]): string[] {
-	const emojiNodes = [] as mfm.MfmEmojiCode[];
+	const emojis = [] as string[];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'emojiCode') emojiNodes.push(node);
-			else if (node.children) scan(node.children);
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'emojiCode' && node.props.name.length <= 100) {
+			emojis.push(node.props.name);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	const emojis = emojiNodes.filter(x => x.props.name.length <= 100).map(x => x.props.name!);
 	return unique(emojis);
 }
diff --git a/src/misc/extract-hashtags.ts b/src/misc/extract-hashtags.ts
index 9961755ccd28e8ea70c5238d16c34f6694548dc5..f89b699a946db82e2c925acb4e56e6a2a0ddbca0 100644
--- a/src/misc/extract-hashtags.ts
+++ b/src/misc/extract-hashtags.ts
@@ -1,18 +1,14 @@
 import * as mfm from 'mfm-js';
 import { unique } from '@/prelude/array';
 
-export default function(nodes: mfm.MfmNode[]): string[] {
-	const hashtagNodes = [] as mfm.MfmHashtag[];
+export function extractHashtags(nodes: mfm.MfmNode[]): string[] {
+	const hashtags = [] as string[];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'hashtag') hashtagNodes.push(node);
-			else if (node.children) scan(node.children);
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'hashtag') {
+			hashtags.push(node.props.hashtag);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	const hashtags = hashtagNodes.map(x => x.props.hashtag);
 	return unique(hashtags);
 }
diff --git a/src/misc/extract-mentions.ts b/src/misc/extract-mentions.ts
index a9d4b378f3d49f27f18617304e1a865a5f467f67..a0e2fb6d5794edc846a9af0053ee26b16f0d30f5 100644
--- a/src/misc/extract-mentions.ts
+++ b/src/misc/extract-mentions.ts
@@ -2,18 +2,15 @@
 
 import * as mfm from 'mfm-js';
 
-export default function(nodes: mfm.MfmNode[]): mfm.MfmMention['props'][] {
+export function extractMentions(nodes: mfm.MfmNode[]): mfm.MfmMention['props'][] {
 	// TODO: 重複を削除
-	const mentionNodes = [] as mfm.MfmMention[];
+	const mentions = [] as mfm.MfmMention['props'][];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'mention') mentionNodes.push(node);
-			else if (node.children) scan(node.children);
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'mention') {
+			mentions.push(node.props);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	return mentionNodes.map(x => x.props);
+	return mentions;
 }
diff --git a/src/misc/extract-url-from-mfm.ts b/src/misc/extract-url-from-mfm.ts
index aa7f5f25408b416cb04091498fd07f6c2b64be2c..ec3b019ea512d742ea66172117682e1163bd538c 100644
--- a/src/misc/extract-url-from-mfm.ts
+++ b/src/misc/extract-url-from-mfm.ts
@@ -6,29 +6,21 @@ import { unique } from '@/prelude/array';
 const removeHash = (x: string) => x.replace(/#[^#]*$/, '');
 
 export function extractUrlFromMfm(nodes: mfm.MfmNode[], respectSilentFlag = true): string[] {
-	const urlNodes = [] as (mfm.MfmUrl | mfm.MfmLink)[];
+	let urls = [] as string[];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'url') {
-				urlNodes.push(node);
-			} else if (node.type === 'link') {
-				if (!respectSilentFlag || !node.props.silent) {
-					urlNodes.push(node);
-				}
-			} else if (node.children) {
-				scan(node.children);
-			}
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'url') {
+			urls.push(node.props.url);
+		} else if (node.type === 'link' && (!respectSilentFlag || !node.props.silent)) {
+			urls.push(node.props.url);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	const urls = unique(urlNodes.map(x => x.props.url));
+	urls = unique(urls);
 
 	return urls.reduce((array, url) => {
-		const removed = removeHash(url);
-		if (!array.map(x => removeHash(x)).includes(removed)) array.push(url);
+		const urlWithoutHash = removeHash(url);
+		if (!array.map(x => removeHash(x)).includes(urlWithoutHash)) array.push(url);
 		return array;
 	}, [] as string[]);
 }
diff --git a/src/server/api/endpoints/i/update.ts b/src/server/api/endpoints/i/update.ts
index 2c20da41c597dff7d51e456c2e16d3d9f540c7d6..c0ffd75e233227965f1ce7cd4a129e7dcac73458 100644
--- a/src/server/api/endpoints/i/update.ts
+++ b/src/server/api/endpoints/i/update.ts
@@ -6,7 +6,7 @@ import acceptAllFollowRequests from '../../../../services/following/requests/acc
 import { publishToFollowers } from '../../../../services/i/update';
 import define from '../../define';
 import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm';
-import extractHashtags from '@/misc/extract-hashtags';
+import { extractHashtags } from '@/misc/extract-hashtags';
 import * as langmap from 'langmap';
 import { updateUsertags } from '../../../../services/update-hashtag';
 import { ApiError } from '../../error';
diff --git a/src/services/note/create.ts b/src/services/note/create.ts
index 125285f34aea86d2c019f5ae2de9802007afe7ae..b9b39d25e4ca13dcdf080308b075db4cfa8a89a1 100644
--- a/src/services/note/create.ts
+++ b/src/services/note/create.ts
@@ -12,9 +12,9 @@ import { updateHashtags } from '../update-hashtag';
 import { concat } from '../../prelude/array';
 import insertNoteUnread from './unread';
 import { registerOrFetchInstanceDoc } from '../register-or-fetch-instance-doc';
-import extractMentions from '@/misc/extract-mentions';
+import { extractMentions } from '@/misc/extract-mentions';
 import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm';
-import extractHashtags from '@/misc/extract-hashtags';
+import { extractHashtags } from '@/misc/extract-hashtags';
 import { Note, IMentionedRemoteUsers } from '../../models/entities/note';
 import { Mutings, Users, NoteWatchings, Notes, Instances, UserProfiles, Antennas, Followings, MutedNotes, Channels, ChannelFollowings } from '../../models';
 import { DriveFile } from '../../models/entities/drive-file';
diff --git a/test/extract-mentions.ts b/test/extract-mentions.ts
index 68b59f7f55a8cd7de581a7b16a1413aa6bfe3234..9e6d041906f0639b7583d23ae5834e00ac4eb792 100644
--- a/test/extract-mentions.ts
+++ b/test/extract-mentions.ts
@@ -1,6 +1,6 @@
 import * as assert from 'assert';
 
-import extractMentions from '../src/misc/extract-mentions';
+import { extractMentions } from '../src/misc/extract-mentions';
 import { parse } from 'mfm-js';
 
 describe('Extract mentions', () => {