diff --git a/core/ast/src/scope.rs b/core/ast/src/scope.rs
index a9177afdf36..254af947cbf 100644
--- a/core/ast/src/scope.rs
+++ b/core/ast/src/scope.rs
@@ -216,11 +216,15 @@ impl Scope {
     #[must_use]
     #[allow(clippy::cast_possible_truncation)]
     pub fn num_bindings_non_local(&self) -> u32 {
+        let arguments = JsString::from("arguments");
+        let bindings = self.inner.bindings.borrow();
+
+        drop(bindings);
         self.inner
             .bindings
             .borrow()
             .iter()
-            .filter(|binding| binding.escapes())
+            .filter(|binding| binding.escapes() || binding.name == arguments)
             .count() as u32
     }
 
diff --git a/core/engine/src/bytecompiler/class.rs b/core/engine/src/bytecompiler/class.rs
index 9e7a00190f2..a5be0e6d742 100644
--- a/core/engine/src/bytecompiler/class.rs
+++ b/core/engine/src/bytecompiler/class.rs
@@ -112,13 +112,34 @@ impl ByteCompiler<'_> {
 
         let value = compiler.register_allocator.alloc();
         if let Some(expr) = &class.constructor {
-            compiler.code_block_flags |= CodeBlockFlags::HAS_FUNCTION_SCOPE;
-            let _ = compiler.push_scope(expr.scopes().function_scope());
+            // function.rs の FunctionCompiler と同じロジックでスコープをpush
+            if let Some(name_scope) = class.name_scope
+                && !name_scope.all_bindings_local()
+            {
+                compiler.code_block_flags |= CodeBlockFlags::HAS_BINDING_IDENTIFIER;
+                let _ = compiler.push_scope(name_scope);
+            }
+
+            let contains_direct_eval = expr.contains_direct_eval();
+            if contains_direct_eval || !expr.scopes().function_scope().all_bindings_local() {
+                compiler.code_block_flags |= CodeBlockFlags::HAS_FUNCTION_SCOPE;
+            } else {
+                compiler.code_block_flags.set(
+                    CodeBlockFlags::HAS_FUNCTION_SCOPE,
+                    expr.scopes().requires_function_scope(),
+                );
+            }
+
+            if compiler.code_block_flags.has_function_scope() {
+                let _ = compiler.push_scope(expr.scopes().function_scope());
+            } else {
+                compiler.variable_scope = expr.scopes().function_scope().clone();
+                compiler.lexical_scope = expr.scopes().function_scope().clone();
+            }
 
             compiler.length = expr.parameters().length();
             compiler.params = expr.parameters().clone();
             compiler.parameter_scope = expr.scopes().parameter_scope();
-
             compiler.function_declaration_instantiation(
                 expr.body(),
                 expr.parameters(),