diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1422f95..5ce62e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,8 +3,12 @@
  * @Author: ekibun
  * @Date: 2020-08-08 08:16:50
  * @LastEditors: ekibun
- * @LastEditTime: 2020-10-03 23:34:30
+ * @LastEditTime: 2020-10-06 23:18:19
 -->
+## 0.1.3
+
+* fix randomly crash by stack overflow.
+
 ## 0.1.2
 
 * fix qjs memory leak.
diff --git a/cxx/ffi.cpp b/cxx/ffi.cpp
index af3bf6c..f23f859 100644
--- a/cxx/ffi.cpp
+++ b/cxx/ffi.cpp
@@ -3,7 +3,7 @@
  * @Author: ekibun
  * @Date: 2020-09-06 18:32:45
  * @LastEditors: ekibun
- * @LastEditTime: 2020-10-03 23:26:14
+ * @LastEditTime: 2020-10-07 00:03:41
  */
 #include "ffi.h"
 #include <functional>
@@ -100,6 +100,7 @@ extern "C"
 
   DLLEXPORT JSValue *jsEval(JSContext *ctx, const char *input, size_t input_len, const char *filename, int32_t eval_flags)
   {
+    JS_ResetStackTop(JS_GetRuntime(ctx));
     return new JSValue(JS_Eval(ctx, input, input_len, filename, eval_flags));
   }
 
@@ -196,6 +197,7 @@ extern "C"
 
   DLLEXPORT const char *jsToCString(JSContext *ctx, JSValueConst *val)
   {
+    JS_ResetStackTop(JS_GetRuntime(ctx));
     return JS_ToCString(ctx, *val);
   }
 
@@ -270,6 +272,7 @@ extern "C"
   DLLEXPORT JSValue *jsCall(JSContext *ctx, JSValueConst *func_obj, JSValueConst *this_obj,
                             int32_t argc, JSValueConst *argv)
   {
+    JS_ResetStackTop(JS_GetRuntime(ctx));
     return new JSValue(JS_Call(ctx, *func_obj, *this_obj, argc, argv));
   }
 
@@ -285,6 +288,7 @@ extern "C"
 
   DLLEXPORT int32_t jsExecutePendingJob(JSRuntime *rt)
   {
+    JS_ResetStackTop(rt);
     JSContext *ctx;
     return JS_ExecutePendingJob(rt, &ctx);
   }
diff --git a/cxx/quickjs b/cxx/quickjs
index 56cbb57..5e8a1f4 160000
--- a/cxx/quickjs
+++ b/cxx/quickjs
@@ -1 +1 @@
-Subproject commit 56cbb57a2e94a02a1bc2b2e75b15612c89fe324d
+Subproject commit 5e8a1f421c00a8aa1d0af2dffd14b30d45832b83
diff --git a/example/pubspec.lock b/example/pubspec.lock
index 312ef0c..681f5fa 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -82,7 +82,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.1.2"
+    version: "0.1.3"
   flutter_test:
     dependency: "direct dev"
     description: flutter
diff --git a/lib/ffi.dart b/lib/ffi.dart
index 89677fb..3950114 100644
--- a/lib/ffi.dart
+++ b/lib/ffi.dart
@@ -3,7 +3,7 @@
  * @Author: ekibun
  * @Date: 2020-09-19 10:29:04
  * @LastEditors: ekibun
- * @LastEditTime: 2020-10-03 23:27:15
+ * @LastEditTime: 2020-10-06 23:13:13
  */
 import 'dart:ffi';
 import 'dart:io';
@@ -478,6 +478,7 @@ String jsToCString(
   Pointer val,
 ) {
   var ptr = _jsToCString(ctx, val);
+  if (ptr.address == 0) throw Exception("JSValue cannot convert to string");
   var str = Utf8.fromUtf8(ptr);
   jsFreeCString(ctx, ptr);
   return str;
diff --git a/lib/flutter_qjs.dart b/lib/flutter_qjs.dart
index ddc0ac8..fb82f24 100644
--- a/lib/flutter_qjs.dart
+++ b/lib/flutter_qjs.dart
@@ -3,7 +3,7 @@
  * @Author: ekibun
  * @Date: 2020-08-08 08:29:09
  * @LastEditors: ekibun
- * @LastEditTime: 2020-10-03 21:55:07
+ * @LastEditTime: 2020-10-06 23:47:13
  */
 import 'dart:async';
 import 'dart:ffi';
@@ -121,6 +121,7 @@ class FlutterQjs {
     var jsval =
         jsEval(_ctx, command, name ?? "<eval>", evalFlags ?? JSEvalType.GLOBAL);
     if (jsIsException(jsval) != 0) {
+      jsFreeValue(_ctx, jsval);
       throw Exception(parseJSException(_ctx));
     }
     var ret = runtimeOpaques[_rt]?.promsieToFuture(jsval);
diff --git a/pubspec.yaml b/pubspec.yaml
index 0537289..c44dee1 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: flutter_qjs
 description: This plugin is a simple js engine for flutter using the `quickjs` project. Plugin currently supports all the platforms except web!
-version: 0.1.2
+version: 0.1.3
 homepage: https://github.com/ekibun/flutter_qjs
 
 environment:
diff --git a/test/flutter_qjs_test.dart b/test/flutter_qjs_test.dart
index ef72181..48eff8c 100644
--- a/test/flutter_qjs_test.dart
+++ b/test/flutter_qjs_test.dart
@@ -3,16 +3,16 @@
  * @Author: ekibun
  * @Date: 2020-09-06 13:02:46
  * @LastEditors: ekibun
- * @LastEditTime: 2020-10-03 21:36:06
+ * @LastEditTime: 2020-10-07 00:11:27
  */
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:flutter_qjs/flutter_qjs.dart';
 import 'package:flutter_qjs/isolate.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 dynamic myMethodHandler(method, args) {
-  print([method, args]);
   return args;
 }
 
@@ -57,7 +57,6 @@ void main() async {
   test('jsToDart', () async {
     final qjs = IsolateQjs(myMethodHandler);
     qjs.setModuleHandler((name) async {
-      print(name);
       return "export default '${new DateTime.now()}'";
     });
     var value = await qjs.evaluate("""
@@ -68,8 +67,19 @@ void main() async {
           0.1, true, false, 1, "world", module
         ]));
       """, name: "<eval>");
-    print(value);
-    print(await value[0]('world'));
+    expect(value[1]['a'], value[1], reason: "recursive object");
+    expect(await value[0]('world'), 'hello world!', reason: "js function call");
+    qjs.close();
+  });
+  test('stack overflow', () async {
+    final qjs = FlutterQjs();
+    try {
+      await qjs.evaluate("a=()=>a();a();", name: "<eval>");
+    } catch (e) {
+      expect(
+          e.toString(), startsWith('Exception: InternalError: stack overflow'),
+          reason: "throw stack overflow");
+    }
     qjs.close();
   });
 }