diff --git a/src/mfm/parse.ts b/src/mfm/parse.ts
index 71e3f25f0..0eb1f810f 100644
--- a/src/mfm/parse.ts
+++ b/src/mfm/parse.ts
@@ -1,4 +1,4 @@
-import parser, { plainParser } from './parser';
+import parser from './parser';
 import { MfmForest } from './types';
 import { normalize } from './normalize';
 
@@ -7,6 +7,6 @@ export default (source: string, plainText = false): MfmForest => {
 		return null;
 	}
 
-	const raw = plainText ? plainParser.root.tryParse(source) : parser.root.tryParse(source) as MfmForest;
+	const raw = plainText ? parser.plain.tryParse(source) : parser.root.tryParse(source) as MfmForest;
 	return normalize(raw);
 };
diff --git a/src/mfm/parser.ts b/src/mfm/parser.ts
index 6ff0ad396..cfa3f5262 100644
--- a/src/mfm/parser.ts
+++ b/src/mfm/parser.ts
@@ -28,29 +28,6 @@ const newline = P((input, i) => {
 	}
 });
 
-export const plainParser = P.createLanguage({
-	root: r => P.alt(
-		r.emoji,
-		r.text
-	).atLeast(1),
-
-	text: () => P.any.map(x => createLeaf('text', { text: x })),
-
-	//#region Emoji
-	emoji: r =>
-		P.alt(
-			P.regexp(/:([a-z0-9_+-]+):/i, 1)
-			.map(x => createLeaf('emoji', {
-				name: x
-			})),
-			P.regexp(emojiRegex)
-			.map(x => createLeaf('emoji', {
-				emoji: x
-			})),
-		),
-	//#endregion
-});
-
 const mfm = P.createLanguage({
 	root: r => P.alt(
 		r.big,
@@ -78,6 +55,11 @@ const mfm = P.createLanguage({
 		r.text
 	).atLeast(1),
 
+	plain: r => P.alt(
+		r.emoji,
+		r.text
+	).atLeast(1),
+
 	text: () => P.any.map(x => createLeaf('text', { text: x })),
 
 	//#region Big
diff --git a/test/mfm.ts b/test/mfm.ts
index 3497c6258..9532b7659 100644
--- a/test/mfm.ts
+++ b/test/mfm.ts
@@ -1091,6 +1091,38 @@ describe('MFM', () => {
 		});
 	});
 
+	describe('plainText', () => {
+		it('text', () => {
+			const tokens = analyze('foo', true);
+			assert.deepStrictEqual(tokens, [
+				text('foo'),
+			]);
+		});
+
+		it('emoji', () => {
+			const tokens = analyze(':foo:', true);
+			assert.deepStrictEqual(tokens, [
+				leaf('emoji', { name: 'foo' })
+			]);
+		});
+
+		it('emoji in text', () => {
+			const tokens = analyze('foo:bar:baz', true);
+			assert.deepStrictEqual(tokens, [
+				text('foo'),
+				leaf('emoji', { name: 'bar' }),
+				text('baz'),
+			]);
+		});
+
+		it('disallow other syntax', () => {
+			const tokens = analyze('foo **bar** baz', true);
+			assert.deepStrictEqual(tokens, [
+				text('foo **bar** baz'),
+			]);
+		});
+	});
+
 	describe('toHtml', () => {
 		it('br', () => {
 			const input = 'foo\nbar\nbaz';