diff --git a/src/backend/commons/common-utils/src/test/java/com/tencent/bk/job/common/util/file/FileSizeUtilTest.java b/src/backend/commons/common-utils/src/test/java/com/tencent/bk/job/common/util/file/FileSizeUtilTest.java
index 64afd5ceb6..b63ddefae4 100644
--- a/src/backend/commons/common-utils/src/test/java/com/tencent/bk/job/common/util/file/FileSizeUtilTest.java
+++ b/src/backend/commons/common-utils/src/test/java/com/tencent/bk/job/common/util/file/FileSizeUtilTest.java
@@ -26,6 +26,7 @@
 
 import org.junit.jupiter.api.Test;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
 
 public class FileSizeUtilTest {
@@ -52,6 +53,8 @@ void testParseFileSizeBytes() {
         assertThat(FileSizeUtil.parseFileSizeBytes("1GB")).isEqualTo(1024L * 1024L * 1024L);
         assertThat(FileSizeUtil.parseFileSizeBytes("1TB")).isEqualTo(1024L * 1024L * 1024L * 1024L);
         assertThat(FileSizeUtil.parseFileSizeBytes("1PB")).isEqualTo(1024L * 1024L * 1024L * 1024L * 1024L);
-        assertThat(FileSizeUtil.parseFileSizeBytes("1XB")).isNull();
+        assertThatThrownBy(() ->
+            FileSizeUtil.parseFileSizeBytes("1XB")
+        ).isInstanceOf(IllegalArgumentException.class);
     }
 }