diff --git a/ets2panda/parser/ETSparserClasses.cpp b/ets2panda/parser/ETSparserClasses.cpp
index 5b48649542721955d09afc7368a88ad5a5da3ed3..a1dbeeea650d4a50365802b3ef214eb93e067b9a 100644
--- a/ets2panda/parser/ETSparserClasses.cpp
+++ b/ets2panda/parser/ETSparserClasses.cpp
@@ -223,6 +223,9 @@ std::tuple<ir::ModifierFlags, bool, bool> ETSParser::ParseClassMemberAccessModif
             accessFlag = ir::ModifierFlags::INTERNAL_PROTECTED;
             break;
         }
+        case lexer::TokenType::EOS: {  // process invalid tokenType
+            return {ir::ModifierFlags::NONE, false, false};
+        }
         default: {
             ES2PANDA_UNREACHABLE();
         }
diff --git a/ets2panda/test/ast/compiler/ets/invalid_access_modifier.ets b/ets2panda/test/ast/compiler/ets/invalid_access_modifier.ets
new file mode 100644
index 0000000000000000000000000000000000000000..14f2dbbba75c0962f18f779e8cfb20e5f98ccfb7
--- /dev/null
+++ b/ets2panda/test/ast/compiler/ets/invalid_access_modifier.ets
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2025 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class A{
+    private \\\\foo(){}
+}
+
+/* @@? 17:13 Error SyntaxError: Invalid character. */
+/* @@? 17:13 Error SyntaxError: Access modifier must precede field and method modifiers. */
+/* @@? 17:14 Error SyntaxError: Invalid character. */
+/* @@? 17:14 Error SyntaxError: Access modifier must precede field and method modifiers. */
+/* @@? 17:15 Error SyntaxError: Invalid character. */
+/* @@? 17:15 Error SyntaxError: Access modifier must precede field and method modifiers. */
+/* @@? 17:16 Error SyntaxError: Invalid character. */
+/* @@? 17:16 Error SyntaxError: Access modifier must precede field and method modifiers. */