diff --git a/CHANGELOG.md b/CHANGELOG.md
index 47372dda56..e77ee9b247 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,9 +10,10 @@
 ## 12.x.x (unreleased)
 
 ### Improvements
-- 依存関係の更新
+- 絵文字オートコンプリートの挙動を改修
 - localStorageのaccountsはindexedDBで保持するように
 - ActivityPub: ジョブキューの試行タイミングを調整 (#7635)
+- 依存関係の更新
 
 ### Bugfixes
 - チャンネルを作成しているとアカウントを削除できないのを修正
diff --git a/src/client/scripts/autocomplete.ts b/src/client/scripts/autocomplete.ts
index 99c54c69c5..924d6a62ee 100644
--- a/src/client/scripts/autocomplete.ts
+++ b/src/client/scripts/autocomplete.ts
@@ -65,7 +65,7 @@ export class Autocomplete {
 	 */
 	private onInput() {
 		const caretPos = this.textarea.selectionStart;
-		const text = this.text.substr(0, caretPos).split('\n').pop();
+		const text = this.text.substr(0, caretPos).split('\n').pop()!;
 
 		const mentionIndex = text.lastIndexOf('@');
 		const hashtagIndex = text.lastIndexOf('#');
@@ -83,7 +83,7 @@ export class Autocomplete {
 
 		const isMention = mentionIndex != -1;
 		const isHashtag = hashtagIndex != -1;
-		const isEmoji = emojiIndex != -1;
+		const isEmoji = emojiIndex != -1 && text.split(/:[a-z0-9_+\-]+:/).pop()!.includes(':');
 
 		let opened = false;