diff --git a/core/Command/Maintenance/UpdateTheme.php b/core/Command/Maintenance/UpdateTheme.php
new file mode 100644
index 0000000000000000000000000000000000000000..f750a142a5f8b1309787096026f258d56aad66b6
--- /dev/null
+++ b/core/Command/Maintenance/UpdateTheme.php
@@ -0,0 +1,64 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Core\Command\Maintenance;
+
+use OC\Core\Command\Maintenance\Mimetype\UpdateJS;
+use OCP\ICacheFactory;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+use OCP\Files\IMimeTypeDetector;
+
+class UpdateTheme extends UpdateJS {
+
+	/** @var IMimeTypeDetector */
+	protected $mimetypeDetector;
+
+	/** @var ICacheFactory */
+	protected $cacheFactory;
+
+	public function __construct(
+		IMimeTypeDetector $mimetypeDetector,
+		ICacheFactory $cacheFactory
+	) {
+		parent::__construct($mimetypeDetector);
+		$this->cacheFactory = $cacheFactory;
+	}
+
+	protected function configure() {
+		$this
+			->setName('maintenance:theme:update')
+			->setDescription('Apply custom theme changes');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+		// run mimetypelist.js update since themes might change mimetype icons
+		parent::execute($input, $output);
+
+		// cleanup image cache
+		$c = $this->cacheFactory->create('imagePath');
+		$c->clear('');
+		$output->writeln('<info>Image cache cleared');
+	}
+}
diff --git a/core/register_command.php b/core/register_command.php
index 629fd183b06a6dade443b57e9b36af90b4e79785..59fc65edbc80896089293fb90c281721f0041650 100644
--- a/core/register_command.php
+++ b/core/register_command.php
@@ -125,6 +125,7 @@ if (\OC::$server->getConfig()->getSystemValue('installed', false)) {
 	$application->add(new OC\Core\Command\Maintenance\Mimetype\UpdateJS(\OC::$server->getMimeTypeDetector()));
 	$application->add(new OC\Core\Command\Maintenance\Mode(\OC::$server->getConfig()));
 	$application->add(new OC\Core\Command\Maintenance\UpdateHtaccess());
+	$application->add(new OC\Core\Command\Maintenance\UpdateTheme(\OC::$server->getMimeTypeDetector(), \OC::$server->getMemCacheFactory()));
 
 	$application->add(new OC\Core\Command\Upgrade(\OC::$server->getConfig(), \OC::$server->getLogger()));
 	$application->add(new OC\Core\Command\Maintenance\Repair(
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 21b7f0c77be001f2bd0ebf83590610437a8254d2..43ed4db930707b0cfd1ec680dcae78273ad6b41c 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -447,6 +447,7 @@ return array(
     'OC\\Core\\Command\\Maintenance\\Mode' => $baseDir . '/core/Command/Maintenance/Mode.php',
     'OC\\Core\\Command\\Maintenance\\Repair' => $baseDir . '/core/Command/Maintenance/Repair.php',
     'OC\\Core\\Command\\Maintenance\\UpdateHtaccess' => $baseDir . '/core/Command/Maintenance/UpdateHtaccess.php',
+    'OC\\Core\\Command\\Maintenance\\UpdateTheme' => $baseDir . '/core/Command/Maintenance/UpdateTheme.php',
     'OC\\Core\\Command\\Security\\ImportCertificate' => $baseDir . '/core/Command/Security/ImportCertificate.php',
     'OC\\Core\\Command\\Security\\ListCertificates' => $baseDir . '/core/Command/Security/ListCertificates.php',
     'OC\\Core\\Command\\Security\\RemoveCertificate' => $baseDir . '/core/Command/Security/RemoveCertificate.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 730116b2566701fa69335ec389c8d88715c0ce27..00b7908f848aa657b0e864d6588e47198fd7b171 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -477,6 +477,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Core\\Command\\Maintenance\\Mode' => __DIR__ . '/../../..' . '/core/Command/Maintenance/Mode.php',
         'OC\\Core\\Command\\Maintenance\\Repair' => __DIR__ . '/../../..' . '/core/Command/Maintenance/Repair.php',
         'OC\\Core\\Command\\Maintenance\\UpdateHtaccess' => __DIR__ . '/../../..' . '/core/Command/Maintenance/UpdateHtaccess.php',
+        'OC\\Core\\Command\\Maintenance\\UpdateTheme' => __DIR__ . '/../../..' . '/core/Command/Maintenance/UpdateTheme.php',
         'OC\\Core\\Command\\Security\\ImportCertificate' => __DIR__ . '/../../..' . '/core/Command/Security/ImportCertificate.php',
         'OC\\Core\\Command\\Security\\ListCertificates' => __DIR__ . '/../../..' . '/core/Command/Security/ListCertificates.php',
         'OC\\Core\\Command\\Security\\RemoveCertificate' => __DIR__ . '/../../..' . '/core/Command/Security/RemoveCertificate.php',
diff --git a/tests/Core/Command/Maintenance/UpdateTheme.php b/tests/Core/Command/Maintenance/UpdateTheme.php
new file mode 100644
index 0000000000000000000000000000000000000000..fbdea0b72b49251b22fd474f4914fc5e3d876239
--- /dev/null
+++ b/tests/Core/Command/Maintenance/UpdateTheme.php
@@ -0,0 +1,82 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Tests\Core\Command\Maintenance;
+
+use OC\Core\Command\Maintenance\Mimetype\UpdateDB;
+use OC\Core\Command\Maintenance\UpdateTheme;
+use OC\Files\Type\Detection;
+use OC\Files\Type\Loader;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Test\TestCase;
+use OCP\Files\IMimeTypeDetector;
+use OCP\Files\IMimeTypeLoader;
+
+class UpdateThemeTest extends TestCase {
+	/** @var IMimeTypeDetector */
+	protected $detector;
+	/** @var ICacheFactory */
+	protected $cacheFactory;
+
+
+	/** @var \PHPUnit_Framework_MockObject_MockObject */
+	protected $consoleInput;
+	/** @var \PHPUnit_Framework_MockObject_MockObject */
+	protected $consoleOutput;
+
+	/** @var \Symfony\Component\Console\Command\Command */
+	protected $command;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$this->detector = $this->createMock(Detection::class);
+		$this->cacheFactory = $this->createMock(ICacheFactory::class);
+
+		$this->consoleInput = $this->getMockBuilder(InputInterface::class)->getMock();
+		$this->consoleOutput = $this->getMockBuilder(OutputInterface::class)->getMock();
+
+		$this->command = new UpdateTheme($this->detector, $this->cacheFactory);
+	}
+
+	public function testThemeUpdate() {
+		$this->consoleInput->method('getOption')
+			->with('maintenance:theme:update')
+			->willReturn(true);
+		$this->detector->expects($this->once())
+			->method('getAllAliases')
+			->willReturn([]);
+		$cache = $this->createMock(ICache::class);
+		$cache->expects($this->once())
+			->method('clear')
+			->with('');
+		$this->cacheFactory->expects($this->once())
+			->method('create')
+			->with('imagePath')
+			->willReturn($cache);
+		self::invokePrivate($this->command, 'execute', [$this->consoleInput, $this->consoleOutput]);
+	}
+}