diff --git a/src/parser/syntaxes/statements.ts b/src/parser/syntaxes/statements.ts
index d8918adf..fef67df7 100644
--- a/src/parser/syntaxes/statements.ts
+++ b/src/parser/syntaxes/statements.ts
@@ -379,7 +379,7 @@ function parseReturn(s: ITokenStream): Ast.Return {
  * StatementWithAttr = *Attr Statement
  * ```
 */
-function parseStatementWithAttr(s: ITokenStream): Ast.Definition {
+export function parseStatementWithAttr(s: ITokenStream): Ast.Definition {
 	const attrs: Ast.Attribute[] = [];
 	while (s.is(TokenKind.OpenSharpBracket)) {
 		attrs.push(parseAttr(s) as Ast.Attribute);
diff --git a/src/parser/syntaxes/toplevel.ts b/src/parser/syntaxes/toplevel.ts
index 91a07787..7a1bed2e 100644
--- a/src/parser/syntaxes/toplevel.ts
+++ b/src/parser/syntaxes/toplevel.ts
@@ -1,7 +1,7 @@
 import { NODE } from '../utils.js';
 import { TokenKind } from '../token.js';
 import { AiScriptSyntaxError, AiScriptUnexpectedEOFError } from '../../error.js';
-import { parseDefStatement, parseStatement } from './statements.js';
+import { parseDefStatement, parseStatement, parseStatementWithAttr } from './statements.js';
 import { parseExpr } from './expressions.js';
 
 import type * as Ast from '../../node.js';
@@ -91,6 +91,10 @@ export function parseNamespace(s: ITokenStream): Ast.Namespace {
 				members.push(parseNamespace(s));
 				break;
 			}
+			case TokenKind.OpenSharpBracket: {
+				members.push(parseStatementWithAttr(s));
+				break;
+			}
 		}
 
 		// terminator
diff --git a/test/index.ts b/test/index.ts
index e66b855b..fa158707 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -929,6 +929,25 @@ describe('Attribute', () => {
 		if (attr.value.type !== 'bool') assert.fail();
 		assert.equal(attr.value.value, true);
 	});
+
+	test.concurrent('attribute with statement under namespace', async () => {
+		const parser = new Parser();
+		const nodes = parser.parse(`
+		:: Tests {
+			#[test]
+			@assert_success() {
+				<: "Hello, world!"
+			}
+		}
+		`);
+		assert.equal(nodes.length, 1);
+		const ns = nodes[0];
+		assert.ok(ns.type === 'ns');
+		const member = ns.members[0];
+		assert.ok(member.type === 'def');
+		const attr = member.attr[0];
+		assert.equal(attr.name, 'test');
+	});
 });
 
 describe('Location', () => {
diff --git a/unreleased/attr-under-ns.md b/unreleased/attr-under-ns.md
new file mode 100644
index 00000000..2cdf909b
--- /dev/null
+++ b/unreleased/attr-under-ns.md
@@ -0,0 +1 @@
+- 名前空間下の変数定義に属性を付与できるようになりました。