diff --git a/src/PhpSpreadsheet/Style/Conditional.php b/src/PhpSpreadsheet/Style/Conditional.php
index 83520722..4cbc2746 100644
--- a/src/PhpSpreadsheet/Style/Conditional.php
+++ b/src/PhpSpreadsheet/Style/Conditional.php
@@ -314,11 +314,7 @@ class Conditional implements IComparable
     }
 
     /**
-     * Verify if param is valid condition type
-     *
-     * @param string $type
-     *
-     * @return bool
+     * Verify if param is valid condition type.
      */
     public static function isValidConditionType(string $type): bool
     {
diff --git a/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalTest.php b/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalTest.php
index 6ee7bc37..8108d988 100644
--- a/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalTest.php
@@ -8,9 +8,8 @@ use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
 
 class ConditionalTest extends AbstractFunctional
 {
-
     /**
-     * Test check if conditional style with type 'notContainsText' works on xlsx
+     * Test check if conditional style with type 'notContainsText' works on xlsx.
      */
     public function testConditionalNotContainsText(): void
     {
@@ -20,12 +19,12 @@ class ConditionalTest extends AbstractFunctional
         $worksheet = $spreadsheet->getActiveSheet();
         $styles = $worksheet->getConditionalStyles('A1:A5');
 
-        $this->assertCount(1, $styles);
+        self::assertCount(1, $styles);
 
-        /** @var $notContainsTextStyle Conditional */
+        /** @var Conditional $notContainsTextStyle */
         $notContainsTextStyle = $styles[0];
-        $this->assertEquals('A', $notContainsTextStyle->getText());
-        $this->assertEquals(Conditional::CONDITION_NOTCONTAINSTEXT, $notContainsTextStyle->getConditionType());
-        $this->assertEquals(Conditional::OPERATOR_NOTCONTAINS, $notContainsTextStyle->getOperatorType());
+        self::assertEquals('A', $notContainsTextStyle->getText());
+        self::assertEquals(Conditional::CONDITION_NOTCONTAINSTEXT, $notContainsTextStyle->getConditionType());
+        self::assertEquals(Conditional::OPERATOR_NOTCONTAINS, $notContainsTextStyle->getOperatorType());
     }
 }
diff --git a/tests/PhpSpreadsheetTests/Writer/Xlsx/ConditionalTest.php b/tests/PhpSpreadsheetTests/Writer/Xlsx/ConditionalTest.php
index 1bcad0d1..21df6ed6 100644
--- a/tests/PhpSpreadsheetTests/Writer/Xlsx/ConditionalTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Xlsx/ConditionalTest.php
@@ -30,7 +30,7 @@ class ConditionalTest extends AbstractFunctional
     }
 
     /**
-     * Test check if conditional style with type 'notContainsText' works on xlsx
+     * Test check if conditional style with type 'notContainsText' works on xlsx.
      */
     public function testConditionalNotContainsText(): void
     {
@@ -40,7 +40,7 @@ class ConditionalTest extends AbstractFunctional
         $condition = new Conditional();
         $condition->setConditionType(Conditional::CONDITION_NOTCONTAINSTEXT);
         $condition->setOperatorType(Conditional::OPERATOR_NOTCONTAINS);
-        $condition->setText("C");
+        $condition->setText('C');
         $condition->getStyle()->applyFromArray([
             'fill' => [
                 'color' => ['argb' => 'FFFFC000'],
@@ -55,6 +55,6 @@ class ConditionalTest extends AbstractFunctional
         $needle = <<<xml
 <conditionalFormatting sqref="A1:A5"><cfRule type="notContainsText" dxfId="" priority="1" operator="notContains" text="C"><formula>ISERROR(SEARCH(&quot;C&quot;,A1:A5))</formula></cfRule></conditionalFormatting>
 xml;
-        $this->assertStringContainsString($needle, $data);
+        self::assertStringContainsString($needle, $data);
     }
 }