diff --git a/crates/oxide_emit/src/prepass/declare.rs b/crates/oxide_emit/src/prepass/declare.rs
index f83e349b..fd748b33 100644
--- a/crates/oxide_emit/src/prepass/declare.rs
+++ b/crates/oxide_emit/src/prepass/declare.rs
@@ -279,6 +279,10 @@ impl Emitter {
     /// 建立 TDZ 占位）。使声明点之前的读取在编译期可分辨为 TDZ 而非隐式全局，
     /// 声明点复用预登记槽位。
     ///
+    /// class 声明绑定外层形态是可变的（`let` 类），`C = null` 合法；类定义期
+    /// 类体（方法/构造器/访问器）对类名的引用由类自身注入的独立不可变绑定承载，
+    /// 不依赖此预声明标志。
+    ///
     /// # 边界与前提
     /// - 只扫描直接子语句；不递归块/if/for/while/switch case/try 区（嵌套块与
     ///   switch CaseBlock 各自预声明；单语句 body 不接受 lexical 声明——lexical
@@ -307,7 +311,7 @@ impl Emitter {
                     if let Some(id) = &cd.id {
                         check_restricted_global_lexical(id.name.as_str(), global_lexical)?;
                         let reg = ctx.alloc_reg();
-                        let _ = ctx.declare_predeclared(id.name.as_str(), reg, VariableDeclarationKind::Const, true);
+                        let _ = ctx.declare_predeclared(id.name.as_str(), reg, VariableDeclarationKind::Let, false);
                     }
                 }
                 Statement::ExportNamedDeclaration(exp) => {
@@ -329,8 +333,8 @@ impl Emitter {
                                     let _ = ctx.declare_predeclared(
                                         id.name.as_str(),
                                         reg,
-                                        VariableDeclarationKind::Const,
-                                        true,
+                                        VariableDeclarationKind::Let,
+                                        false,
                                     );
                                 }
                             }
@@ -343,8 +347,7 @@ impl Emitter {
                         if let Some(id) = &cd.id {
                             check_restricted_global_lexical(id.name.as_str(), global_lexical)?;
                             let reg = ctx.alloc_reg();
-                            let _ =
-                                ctx.declare_predeclared(id.name.as_str(), reg, VariableDeclarationKind::Const, true);
+                            let _ = ctx.declare_predeclared(id.name.as_str(), reg, VariableDeclarationKind::Let, false);
                         }
                     }
                     ExportDefaultDeclarationKind::FunctionDeclaration(fd) => {
diff --git a/crates/oxide_vm/tests/class_tests.rs b/crates/oxide_vm/tests/class_tests.rs
index a39b50f4..76432ec7 100644
--- a/crates/oxide_vm/tests/class_tests.rs
+++ b/crates/oxide_vm/tests/class_tests.rs
@@ -853,3 +853,12 @@ fn class_declaration_captured_name_cell_still_initialized() {
     .unwrap();
     assert_num(result, 51.0);
 }
+
+// 类声明的外层绑定是可变的（let 类）：顶层重赋类名合法并生效。
+// 类体内对类名的引用另由独立不可变绑定承载，见 name-binding/const.js 语料。
+#[test]
+fn class_declaration_outer_binding_is_mutable() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "class A { m(){ return 1; } } A = 1; A").unwrap();
+    assert_num(result, 1.0);
+}
diff --git a/crates/oxide_vm/tests/module_top_completion_tests.rs b/crates/oxide_vm/tests/module_top_completion_tests.rs
index 017eb64b..ff9c14f5 100644
--- a/crates/oxide_vm/tests/module_top_completion_tests.rs
+++ b/crates/oxide_vm/tests/module_top_completion_tests.rs
@@ -96,3 +96,19 @@ fn dependent_module_namespace_contract_intact() {
     let r = probe(&mut vm, "globalThis.__dep === true");
     assert!(r.is_bool() && r.as_bool(), "依赖命名空间值应正确流入，实际 {r:?}");
 }
+
+#[test]
+fn exported_class_declaration_binding_is_mutable() {
+    // 模块顶层 class 外层绑定是可变 let 类：`export class` 与具名
+    // `export default class` 均允许声明后重赋（CreateMutableBinding）。
+    let allocator = oxide_parser::Allocator::default();
+    let source = "export class C {}\nC = null;\nexport default class D {}\nD = null;\nglobalThis.__mutable = C === null && D === null;";
+    let program = oxide_parser::parse_module(&allocator, source).expect("parse module");
+    let module = Compiler::new()
+        .compile_module(&program, "test.mjs", &mut FileLoader)
+        .expect("compile module");
+    let mut vm = Vm::new();
+    vm.run(&Arc::new(module)).expect("module run");
+    let r = probe(&mut vm, "globalThis.__mutable === true");
+    assert!(r.is_bool() && r.as_bool(), "模块 class 外层绑定应可重赋，实际 {r:?}");
+}