diff --git a/tests/PhpSpreadsheetTests/SampleTest.php b/tests/PhpSpreadsheetTests/Helper/SampleTest.php
similarity index 96%
rename from tests/PhpSpreadsheetTests/SampleTest.php
rename to tests/PhpSpreadsheetTests/Helper/SampleTest.php
index 19e6fea9..9022d6e4 100644
--- a/tests/PhpSpreadsheetTests/SampleTest.php
+++ b/tests/PhpSpreadsheetTests/Helper/SampleTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace PhpOffice\PhpSpreadsheetTests;
+namespace PhpOffice\PhpSpreadsheetTests\Sample;
 
 use PhpOffice\PhpSpreadsheet\Helper\Sample;
 use PHPUnit_Framework_TestCase;
diff --git a/tests/PhpSpreadsheetTests/Reader/HTMLTest.php b/tests/PhpSpreadsheetTests/Reader/HtmlTest.php
similarity index 87%
rename from tests/PhpSpreadsheetTests/Reader/HTMLTest.php
rename to tests/PhpSpreadsheetTests/Reader/HtmlTest.php
index 362d7fe6..a3ca4892 100644
--- a/tests/PhpSpreadsheetTests/Reader/HTMLTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/HtmlTest.php
@@ -5,7 +5,7 @@ namespace PhpOffice\PhpSpreadsheetTests\Reader;
 use PhpOffice\PhpSpreadsheet\Reader\Html;
 use PHPUnit_Framework_TestCase;
 
-class HTMLTest extends PHPUnit_Framework_TestCase
+class HtmlTest extends PHPUnit_Framework_TestCase
 {
     public function testCsvWithAngleBracket()
     {
diff --git a/tests/PhpSpreadsheetTests/Reader/XLSXTest.php b/tests/PhpSpreadsheetTests/Reader/XlsxTest.php
similarity index 88%
rename from tests/PhpSpreadsheetTests/Reader/XLSXTest.php
rename to tests/PhpSpreadsheetTests/Reader/XlsxTest.php
index aab9c6ea..ce466f8a 100644
--- a/tests/PhpSpreadsheetTests/Reader/XLSXTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/XlsxTest.php
@@ -5,7 +5,7 @@ namespace PhpOffice\PhpSpreadsheetTests\Reader;
 use PhpOffice\PhpSpreadsheet\Reader\Xlsx;
 use PHPUnit_Framework_TestCase;
 
-class XLSXTest extends PHPUnit_Framework_TestCase
+class XlsxTest extends PHPUnit_Framework_TestCase
 {
     /**
      * Test load Xlsx file without cell reference.
diff --git a/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php b/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php
deleted file mode 100644
index c9cc3d00..00000000
--- a/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-namespace PhpOffice\PhpSpreadsheetTests\Style;
-
-use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
-use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
-use PHPUnit_Framework_TestCase;
-
-class NumberFormatDateTest extends PHPUnit_Framework_TestCase
-{
-    public function setUp()
-    {
-        StringHelper::setDecimalSeparator('.');
-        StringHelper::setThousandsSeparator(',');
-    }
-
-    /**
-     * @dataProvider providerNumberFormat
-     *
-     * @param mixed $expectedResult
-     */
-    public function testFormatValueWithMask($expectedResult, ...$args)
-    {
-        $result = NumberFormat::toFormattedString(...$args);
-        self::assertEquals($expectedResult, $result);
-    }
-
-    public function providerNumberFormat()
-    {
-        return require 'data/Style/NumberFormatDates.php';
-    }
-}
diff --git a/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php b/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
index f0b5647a..9c38c758 100644
--- a/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
+++ b/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
@@ -29,4 +29,20 @@ class NumberFormatTest extends PHPUnit_Framework_TestCase
     {
         return require 'data/Style/NumberFormat.php';
     }
+
+    /**
+     * @dataProvider providerNumberFormatDates
+     *
+     * @param mixed $expectedResult
+     */
+    public function testFormatValueWithMaskDate($expectedResult, ...$args)
+    {
+        $result = NumberFormat::toFormattedString(...$args);
+        self::assertEquals($expectedResult, $result);
+    }
+
+    public function providerNumberFormatDates()
+    {
+        return require 'data/Style/NumberFormatDates.php';
+    }
 }
diff --git a/tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php b/tests/PhpSpreadsheetTests/Worksheet/ColumnTest.php
similarity index 95%
rename from tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php
rename to tests/PhpSpreadsheetTests/Worksheet/ColumnTest.php
index ea47cd64..02a9f3c0 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/ColumnTest.php
@@ -7,7 +7,7 @@ use PhpOffice\PhpSpreadsheet\Worksheet\ColumnCellIterator;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 use PHPUnit_Framework_TestCase;
 
-class WorksheetColumnTest extends PHPUnit_Framework_TestCase
+class ColumnTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockColumn;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php b/tests/PhpSpreadsheetTests/Worksheet/RowTest.php
similarity index 95%
rename from tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php
rename to tests/PhpSpreadsheetTests/Worksheet/RowTest.php
index cec755b6..6b215601 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/RowTest.php
@@ -7,7 +7,7 @@ use PhpOffice\PhpSpreadsheet\Worksheet\RowCellIterator;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 use PHPUnit_Framework_TestCase;
 
-class WorksheetRowTest extends PHPUnit_Framework_TestCase
+class RowTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockRow;