diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..df30947
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+
+.idea/
diff --git a/src/Exporters/Sheet.php b/src/Exporters/Sheet.php
index 323cdbf..455a843 100644
--- a/src/Exporters/Sheet.php
+++ b/src/Exporters/Sheet.php
@@ -120,7 +120,7 @@ public function getHeadingStyle()
      * @param string $name
      * @return $this
      */
-    public function name($name)
+    public function name(?string $name)
     {
         if (is_string($name)) {
             $this->name = $name;
diff --git a/tests/Exporters/XLSX/WithChunkQueryTest.php b/tests/Exporters/XLSX/WithChunkQueryTest.php
index e578dd6..7a58c7e 100644
--- a/tests/Exporters/XLSX/WithChunkQueryTest.php
+++ b/tests/Exporters/XLSX/WithChunkQueryTest.php
@@ -32,7 +32,7 @@ public function testStore()
             ->store($storePath);
 
         // 读取
-        $this->assertSingleSheet($storePath, 'Sheet1', $users);
+        $this->assertSingleSheet($storePath, '0', $users);
 
         /*
          |---------------------------------------------------------------
@@ -81,7 +81,7 @@ public function testRaw()
         file_put_contents($storePath, $contents);
 
         // 读取
-        $this->assertSingleSheet($storePath, 'Sheet1', $users);
+        $this->assertSingleSheet($storePath, '0', $users);
 
         /*
          |---------------------------------------------------------------
diff --git a/tests/Exporters/XLSX/WithSheetTest.php b/tests/Exporters/XLSX/WithSheetTest.php
index c658e28..8ddf7ce 100644
--- a/tests/Exporters/XLSX/WithSheetTest.php
+++ b/tests/Exporters/XLSX/WithSheetTest.php
@@ -24,6 +24,7 @@ public function test()
         $storePath = $this->generateTempFilePath('xlsx');
 
         $sheet = Excel::createSheet($users)
+            ->name('test')
             ->headingStyle(
                 (new StyleBuilder)
                     ->setFontColor(Color::BLUE)
@@ -43,7 +44,7 @@ public function test()
         Excel::export($sheet)->store($storePath);
 
         // 读取
-        $this->assertSingleSheet($storePath, 'Sheet1', $users);
+        $this->assertSingleSheet($storePath, 'test', $users);
 
         /*
         |---------------------------------------------------------------