diff --git a/core/src/test/java/com/alibaba/fastjson2/issues/Issue661.java b/core/src/test/java/com/alibaba/fastjson2/issues/Issue661.java
new file mode 100644
index 0000000000..78d996f661
--- /dev/null
+++ b/core/src/test/java/com/alibaba/fastjson2/issues/Issue661.java
@@ -0,0 +1,39 @@
+package com.alibaba.fastjson2.issues;
+
+import com.alibaba.fastjson2.JSON;
+import lombok.Data;
+import org.junit.jupiter.api.RepeatedTest;
+
+import java.util.Collections;
+
+public class Issue661 {
+    @Data
+    static class Response<T> {
+        T data;
+
+        Response(T data) {
+            this.data = data;
+        }
+    }
+
+    @Data
+    static class A {
+        // 没有属性不会异常
+        int a;
+    }
+
+    @RepeatedTest(100)
+    void testB() {
+        for (int i = 0; i < 1000; i++) {
+            JSON.toJSONString(new Response<>(new A()));
+        }
+    }
+
+    @RepeatedTest(100)
+    void testList() {
+        for (int i = 0; i < 1000; i++) {
+            // Collections.singletonList(0)改成0也会异常，异常概率小一些
+            JSON.toJSONString(new Response<>(Collections.singletonList(0)));
+        }
+    }
+}
diff --git a/fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue661.java b/fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue661.java
new file mode 100644
index 0000000000..4c23448d60
--- /dev/null
+++ b/fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue661.java
@@ -0,0 +1,39 @@
+package com.alibaba.fastjson.v2issues;
+
+import com.alibaba.fastjson.JSON;
+import lombok.Data;
+import org.junit.jupiter.api.RepeatedTest;
+
+import java.util.Collections;
+
+public class Issue661 {
+    @Data
+    static class Response<T> {
+        T data;
+
+        Response(T data) {
+            this.data = data;
+        }
+    }
+
+    @Data
+    static class A {
+        // 没有属性不会异常
+        int a;
+    }
+
+    @RepeatedTest(100)
+    void testB() {
+        for (int i = 0; i < 1000; i++) {
+            JSON.toJSONString(new Response<>(new A()));
+        }
+    }
+
+    @RepeatedTest(100)
+    void testList() {
+        for (int i = 0; i < 1000; i++) {
+            // Collections.singletonList(0)改成0也会异常，异常概率小一些
+            JSON.toJSONString(new Response<>(Collections.singletonList(0)));
+        }
+    }
+}