diff --git a/libraries/classes/Config.php b/libraries/classes/Config.php
index 4ba9cbdb9a..675296033b 100644
--- a/libraries/classes/Config.php
+++ b/libraries/classes/Config.php
@@ -1673,7 +1673,7 @@ class Config
         if (empty($path)) {
             $path = null;
         } else {
-            $path .= '/' . $name;
+            $path = rtrim($path, DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR . $name;
             if (! @is_dir($path)) {
                 @mkdir($path, 0770, true);
             }
diff --git a/test/classes/ConfigTest.php b/test/classes/ConfigTest.php
index f32f9005d0..be234167ce 100644
--- a/test/classes/ConfigTest.php
+++ b/test/classes/ConfigTest.php
@@ -1007,6 +1007,39 @@ class ConfigTest extends PmaTestCase
         );
     }
 
+    /**
+     * Test for getTempDir
+     *
+     * @return void
+     *
+     * @group file-system
+     */
+    public function testGetTempDir(): void
+    {
+        $this->object->set('TempDir', sys_get_temp_dir() . DIRECTORY_SEPARATOR);
+        // Check no double slash is here
+        $this->assertEquals(
+            sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'upload',
+            $this->object->getTempDir('upload')
+        );
+    }
+
+    /**
+     * Test for getUploadTempDir
+     *
+     * @return void
+     *
+     * @group file-system
+     */
+    public function testGetUploadTempDir(): void
+    {
+        $this->object->set('TempDir', sys_get_temp_dir() . DIRECTORY_SEPARATOR);
+        $this->assertEquals(
+            $this->object->getTempDir('upload'),
+            $this->object->getUploadTempDir()
+        );
+    }
+
     /**
      * Test for isGitRevision
      *