diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java
index 33cafcc720..a3f6942528 100644
--- a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java
+++ b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java
@@ -3179,7 +3179,7 @@ public final void writeString(int value) {
 
     @Override
     public final void writeString(long value) {
-        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) == 0;
+        boolean writeAsString = (context.features & (WriteNonStringValueAsString.mask | WriteLongAsString.mask)) == 0;
         if (writeAsString) {
             writeQuote();
         }
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java
index e864c9b900..a193b51860 100644
--- a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java
+++ b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java
@@ -375,7 +375,7 @@ public final void writeString(boolean value) {
 
     @Override
     public final void writeString(byte value) {
-        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) != 0;
+        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) == 0;
         if (writeAsString) {
             writeQuote();
         }
@@ -387,7 +387,7 @@ public final void writeString(byte value) {
 
     @Override
     public final void writeString(short value) {
-        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) != 0;
+        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) == 0;
         if (writeAsString) {
             writeQuote();
         }
@@ -399,7 +399,7 @@ public final void writeString(short value) {
 
     @Override
     public final void writeString(int value) {
-        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) != 0;
+        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) == 0;
         if (writeAsString) {
             writeQuote();
         }
@@ -411,7 +411,7 @@ public final void writeString(int value) {
 
     @Override
     public final void writeString(long value) {
-        boolean writeAsString = (context.features & WriteNonStringValueAsString.mask) != 0;
+        boolean writeAsString = (context.features & (WriteNonStringValueAsString.mask | WriteLongAsString.mask)) == 0;
         if (writeAsString) {
             writeQuote();
         }
diff --git a/core/src/test/java/com/alibaba/fastjson2/issues_2400/Issue2431.java b/core/src/test/java/com/alibaba/fastjson2/issues_2400/Issue2431.java
index 28f39323bd..363698b07d 100644
--- a/core/src/test/java/com/alibaba/fastjson2/issues_2400/Issue2431.java
+++ b/core/src/test/java/com/alibaba/fastjson2/issues_2400/Issue2431.java
@@ -27,6 +27,10 @@ public void test() {
                 "{\"b\":\"1\",\"d\":\"1.0\",\"f\":\"1.0\",\"i\":\"1\",\"l\":\"1\",\"s\":\"1\",\"z\":\"false\"}",
                 JSON.toJSONString(bean));
 
+        assertEquals(
+                "{\"b\":\"1\",\"d\":\"1.0\",\"f\":\"1.0\",\"i\":\"1\",\"l\":\"1\",\"s\":\"1\",\"z\":\"false\"}",
+                new String(JSON.toJSONBytes(bean)));
+
         byte[] bytes = JSONB.toBytes(bean);
         String str2 = JSONB.toJSONString(bytes);
         assertEquals("{\n" +
@@ -66,6 +70,10 @@ public void test1() {
                 "{\"b\":\"1\",\"d\":\"1.0\",\"f\":\"1.0\",\"i\":\"1\",\"l\":\"1\",\"s\":\"1\",\"z\":\"false\"}",
                 JSON.toJSONString(bean));
 
+        assertEquals(
+                "{\"b\":\"1\",\"d\":\"1.0\",\"f\":\"1.0\",\"i\":\"1\",\"l\":\"1\",\"s\":\"1\",\"z\":\"false\"}",
+                new String(JSON.toJSONBytes(bean)));
+
         byte[] bytes = JSONB.toBytes(bean);
         String str2 = JSONB.toJSONString(bytes);
         assertEquals("{\n" +
@@ -106,6 +114,14 @@ public void test2() {
                 "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
                 JSON.toJSONString(bean));
 
+        assertEquals(
+                "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
+                new String(JSON.toJSONBytes(bean)));
+
+        assertEquals(
+                "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
+                new String(JSON.toJSONBytes(bean)));
+
         byte[] bytes = JSONB.toBytes(bean);
         String str2 = JSONB.toJSONString(bytes);
         assertEquals("{\n" +
@@ -146,6 +162,10 @@ public void test3() {
                 "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
                 JSON.toJSONString(bean));
 
+        assertEquals(
+                "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
+                new String(JSON.toJSONBytes(bean)));
+
         byte[] bytes = JSONB.toBytes(bean);
         String str2 = JSONB.toJSONString(bytes);
         assertEquals("{\n" +
@@ -186,6 +206,10 @@ public void test4() {
                 "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
                 JSON.toJSONString(bean));
 
+        assertEquals(
+                "{\"bs\":[\"1\"],\"ds\":[\"1.0\"],\"fs\":[\"1.0\"],\"is\":[\"1\"],\"ls\":[\"1\"],\"ss\":[\"1\"],\"zs\":[\"false\"]}",
+                new String(JSON.toJSONBytes(bean)));
+
         byte[] bytes = JSONB.toBytes(bean);
         String str2 = JSONB.toJSONString(bytes);
         assertEquals("{\n" +