diff --git a/test/PHPMailer/MbPathinfoTest.php b/test/PHPMailer/MbPathinfoTest.php
new file mode 100644
index 00000000..d996c053
--- /dev/null
+++ b/test/PHPMailer/MbPathinfoTest.php
@@ -0,0 +1,172 @@
+<?php
+
+/**
+ * PHPMailer - PHP email transport unit tests.
+ * PHP version 5.5.
+ *
+ * @author    Marcus Bointon <phpmailer@synchromedia.co.uk>
+ * @author    Andy Prevost
+ * @copyright 2012 - 2020 Marcus Bointon
+ * @copyright 2004 - 2009 Andy Prevost
+ * @license   http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
+ */
+
+namespace PHPMailer\Test\PHPMailer;
+
+use PHPMailer\PHPMailer\PHPMailer;
+use Yoast\PHPUnitPolyfills\TestCases\TestCase;
+
+/**
+ * Test Multi-byte-safe pathinfo replacement functionality.
+ *
+ * @covers \PHPMailer\PHPMailer\PHPMailer::mb_pathinfo
+ */
+final class MbPathinfoTest extends TestCase
+{
+
+    /**
+     * Verify retrieving information about a file path when the $options parameter has been passed.
+     *
+     * @dataProvider dataMb_pathinfoWithoutOptions
+     *
+     * @param string $path     Path input.
+     * @param string $expected Expected function output.
+     */
+    public function testMb_pathinfoWithoutOptions($path, $expected)
+    {
+        $result = PHPMailer::mb_pathinfo($path);
+        self::assertSame($expected, $result);
+    }
+
+    /**
+     * Data provider.
+     *
+     * @return array
+     */
+    public function dataMb_pathinfoWithoutOptions()
+    {
+        return [
+            'Empty string' => [
+                'path'     => '',
+                'expected' => [
+                    'dirname'   => '',
+                    'basename'  => '',
+                    'extension' => '',
+                    'filename'  => '',
+                ],
+            ],
+            'Unix path with singlebyte filename' => [
+                'path'     => '/mnt/music/music.mp3',
+                'expected' => [
+                    'dirname'   => '/mnt/music',
+                    'basename'  => 'music.mp3',
+                    'extension' => 'mp3',
+                    'filename'  => 'music',
+                ],
+            ],
+            'Windows path with singlebyte filename' => [
+                'path'     => 'c:\mnt\music\music.mp3',
+                'expected' => [
+                    'dirname'   => 'c:\mnt\music',
+                    'basename'  => 'music.mp3',
+                    'extension' => 'mp3',
+                    'filename'  => 'music',
+                ],
+            ],
+            'Unix path with multibyte filename' => [
+                'path'     => '/mnt/files/飛兒樂 團光茫.mp3',
+                'expected' => [
+                    'dirname'   => '/mnt/files',
+                    'basename'  => '飛兒樂 團光茫.mp3',
+                    'extension' => 'mp3',
+                    'filename'  => '飛兒樂 團光茫',
+                ],
+            ],
+            'Windows path with multibyte filename' => [
+                'path'     => 'c:\mnt\files\飛兒樂 團光茫.mp3',
+                'expected' => [
+                    'dirname'   => 'c:\mnt\files',
+                    'basename'  => '飛兒樂 團光茫.mp3',
+                    'extension' => 'mp3',
+                    'filename'  => '飛兒樂 團光茫',
+                ],
+            ],
+            'Filename, not path, contains spaces' => [
+                'path'     => 'my file.png',
+                'expected' => [
+                    'dirname'   => '',
+                    'basename'  => 'my file.png',
+                    'extension' => 'png',
+                    'filename'  => 'my file',
+                ],
+            ],
+            'Path, no file name, linux style, contains spaces' => [
+                'path'     => '/mnt/sub directory/another sub/',
+                'expected' => [
+                    'dirname'   => '/mnt/sub directory',
+                    'basename'  => 'another sub',
+                    'extension' => '',
+                    'filename'  => 'another sub',
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Verify retrieving information about a file path when the $options parameter has been passed.
+     *
+     * @dataProvider dataMb_pathinfoWithOptions
+     *
+     * @param int|string $options  Input to pass to the $options parameter.
+     * @param string     $expected Expected function output.
+     */
+    public function testMb_pathinfoWithOptions($options, $expected)
+    {
+        $path   = '/mnt/files/飛兒樂 團光茫.mp3';
+        $result = PHPMailer::mb_pathinfo($path, $options);
+        self::assertSame($expected, $result);
+    }
+
+    /**
+     * Data provider.
+     *
+     * @return array
+     */
+    public function dataMb_pathinfoWithOptions()
+    {
+        return [
+            'Option: PATHINFO_DIRNAME' => [
+                'options'  => PATHINFO_DIRNAME,
+                'expected' => '/mnt/files',
+            ],
+            'Option: PATHINFO_BASENAME' => [
+                'options'  => PATHINFO_BASENAME,
+                'expected' => '飛兒樂 團光茫.mp3',
+            ],
+            'Option: PATHINFO_EXTENSION' => [
+                'options'  => PATHINFO_EXTENSION,
+                'expected' => 'mp3',
+            ],
+            'Option: PATHINFO_FILENAME' => [
+                'options'  => PATHINFO_FILENAME,
+                'expected' => '飛兒樂 團光茫',
+            ],
+            'Option: dirname' => [
+                'options'  => 'dirname',
+                'expected' => '/mnt/files',
+            ],
+            'Option: basename' => [
+                'options'  => 'basename',
+                'expected' => '飛兒樂 團光茫.mp3',
+            ],
+            'Option: extension' => [
+                'options'  => 'extension',
+                'expected' => 'mp3',
+            ],
+            'Option: filename' => [
+                'options'  => 'filename',
+                'expected' => '飛兒樂 團光茫',
+            ],
+        ];
+    }
+}
diff --git a/test/PHPMailer/PHPMailerTest.php b/test/PHPMailer/PHPMailerTest.php
index 60ad810b..91f10d06 100644
--- a/test/PHPMailer/PHPMailerTest.php
+++ b/test/PHPMailer/PHPMailerTest.php
@@ -1350,30 +1350,6 @@ EOT;
         self::assertTrue($this->Mail->set('Timeout', 11), 'Valid property set failed');
         self::assertTrue($this->Mail->set('AllowEmpty', null), 'Null property set failed');
         self::assertTrue($this->Mail->set('AllowEmpty', false), 'Valid property set of null property failed');
-        //Test pathinfo
-        $a = '/mnt/files/飛兒樂 團光茫.mp3';
-        $q = PHPMailer::mb_pathinfo($a);
-        self::assertSame('/mnt/files', $q['dirname'], 'UNIX dirname not matched');
-        self::assertSame('飛兒樂 團光茫.mp3', $q['basename'], 'UNIX basename not matched');
-        self::assertSame('mp3', $q['extension'], 'UNIX extension not matched');
-        self::assertSame('飛兒樂 團光茫', $q['filename'], 'UNIX filename not matched');
-        self::assertSame(
-            '/mnt/files',
-            PHPMailer::mb_pathinfo($a, PATHINFO_DIRNAME),
-            'Dirname path element not matched'
-        );
-        self::assertSame(
-            '飛兒樂 團光茫.mp3',
-            PHPMailer::mb_pathinfo($a, PATHINFO_BASENAME),
-            'Basename path element not matched'
-        );
-        self::assertSame('飛兒樂 團光茫', PHPMailer::mb_pathinfo($a, 'filename'), 'Filename path element not matched');
-        $a = 'c:\mnt\files\飛兒樂 團光茫.mp3';
-        $q = PHPMailer::mb_pathinfo($a);
-        self::assertSame('c:\mnt\files', $q['dirname'], 'Windows dirname not matched');
-        self::assertSame('飛兒樂 團光茫.mp3', $q['basename'], 'Windows basename not matched');
-        self::assertSame('mp3', $q['extension'], 'Windows extension not matched');
-        self::assertSame('飛兒樂 團光茫', $q['filename'], 'Windows filename not matched');
     }
 
     public function testBadSMTP()