diff --git a/CHANGELOG.md b/CHANGELOG.md
index 83ad7dc3fe..fd63792374 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,6 +35,7 @@
 * 【db     】      修复`SqlUtil.removeOuterOrderBy`处理没有order by的语句导致异常问题（pr#4089@Github）
 * 【extra  】      修复`Sftp.upload`目标路径为null时空指针问题（issue#ID14WX@Gitee）
 * 【ai     】      修复`AIConfigBuilder`中方法名拼写错误（pr#1382@Gitee）
+* 【core   】      修复`StrBuilder`charAt越界判断错误（pr#4094@Github）
 
 -------------------------------------------------------------------------------------------------------------
 # 5.8.40(2025-08-26)
diff --git a/hutool-core/src/test/java/cn/hutool/core/text/StrBuilderTest.java b/hutool-core/src/test/java/cn/hutool/core/text/StrBuilderTest.java
index 52f2d92223..04a277af40 100644
--- a/hutool-core/src/test/java/cn/hutool/core/text/StrBuilderTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/text/StrBuilderTest.java
@@ -135,9 +135,9 @@ public class StrBuilderTest {
 	@Test
 	void charAtTest() {
 		final StrBuilder helloWorld = StrBuilder.create("Hello World");
-		Assertions.assertEquals(helloWorld.charAt(-1),'d');
-		Assertions.assertEquals(helloWorld.charAt(0),'H');
-		Assertions.assertEquals(helloWorld.charAt(10),'d');
+		Assertions.assertEquals('d', helloWorld.charAt(-1));
+		Assertions.assertEquals('H', helloWorld.charAt(0));
+		Assertions.assertEquals('d', helloWorld.charAt(10));
 		Assertions.assertThrows(StringIndexOutOfBoundsException.class, () -> helloWorld.charAt(11));;
 	}
 }