diff --git a/config/config.sample.php b/config/config.sample.php
index 380bc62016c5..da8329606d7b 100644
--- a/config/config.sample.php
+++ b/config/config.sample.php
@@ -1240,6 +1240,11 @@
 		'.htaccess',
 		'.user.ini',
 	),
+/**
+ * The list of apps that are allowed to have no signature.json
+ */
+'integrity.ignore.missing.app.signature' => [],
+
 /**
  * Define a default folder for shared files and folders other than root.
  */
diff --git a/lib/private/IntegrityCheck/Checker.php b/lib/private/IntegrityCheck/Checker.php
index e02a57e15ab1..e26649145179 100644
--- a/lib/private/IntegrityCheck/Checker.php
+++ b/lib/private/IntegrityCheck/Checker.php
@@ -26,6 +26,7 @@
 namespace OC\IntegrityCheck;
 
 use OC\IntegrityCheck\Exceptions\InvalidSignatureException;
+use OC\IntegrityCheck\Exceptions\MissingSignatureException;
 use OC\IntegrityCheck\Helpers\AppLocator;
 use OC\IntegrityCheck\Helpers\EnvironmentHelper;
 use OC\IntegrityCheck\Helpers\FileAccessHelper;
@@ -316,6 +317,7 @@ public function writeCoreSignature(X509 $certificate,
 	 * @param boolean $force
 	 * @return array
 	 * @throws InvalidSignatureException
+	 * @throws MissingSignatureException
 	 * @throws \Exception
 	 */
 	private function verify($signaturePath, $basePath, $certificateCN, $force = false) {
@@ -325,7 +327,7 @@ private function verify($signaturePath, $basePath, $certificateCN, $force = fals
 
 		$signatureData = json_decode($this->fileAccessHelper->file_get_contents($signaturePath), true);
 		if(!is_array($signatureData)) {
-			throw new InvalidSignatureException('Signature data not found.');
+			throw new MissingSignatureException('Signature data not found.');
 		}
 
 		$expectedHashes = $signatureData['hashes'];
@@ -485,6 +487,21 @@ private function getSystemValue($key, $default = '') {
 		return $default;
 	}
 
+	/**
+	 * Get a list of apps that are allowed to have no signature.json
+	 * @return string[]
+	 */
+	private function getIgnoredUnsignedApps() {
+		$ignoredUnsignedApps = $this->getSystemValue(
+			'integrity.ignore.missing.app.signature',
+			[]
+		);
+		if (is_array($ignoredUnsignedApps)===false) {
+			$ignoredUnsignedApps = [];
+		}
+		return $ignoredUnsignedApps;
+	}
+
 	/**
 	 * Sanity wrapper for getAppValue
 	 * @param string $key
@@ -554,15 +571,27 @@ private function deleteAppValue($key) {
 	 */
 	public function verifyAppSignature($appId, $path = '', $force = false) {
 		try {
-			if($path === '') {
+			if ($path === '') {
 				$path = $this->appLocator->getAppPath($appId);
 			}
+
 			$result = $this->verify(
-					$path . '/appinfo/signature.json',
-					$path,
-					$appId,
-					$force
+				$path . '/appinfo/signature.json',
+				$path,
+				$appId,
+				$force
 			);
+		} catch (MissingSignatureException $e) {
+			if (!in_array($appId, $this->getIgnoredUnsignedApps())) {
+				$result = [
+					'EXCEPTION' => [
+						'class' => get_class($e),
+						'message' => $e->getMessage(),
+					],
+				];
+			} else {
+				$result = [];
+			}
 		} catch (\Exception $e) {
 			$result = [
 					'EXCEPTION' => [
diff --git a/lib/private/IntegrityCheck/Exceptions/MissingSignatureException.php b/lib/private/IntegrityCheck/Exceptions/MissingSignatureException.php
new file mode 100644
index 000000000000..626a8154d87f
--- /dev/null
+++ b/lib/private/IntegrityCheck/Exceptions/MissingSignatureException.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ * @author Viktar Dubiniuk <dubiniuk@owncloud.com>
+ *
+ * @copyright Copyright (c) 2018, ownCloud GmbH
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\IntegrityCheck\Exceptions;
+
+/**
+ * Class MissingSignatureException
+ *
+ * @package OC\IntegrityCheck\Exceptions
+ */
+class MissingSignatureException extends InvalidSignatureException {
+}
diff --git a/tests/lib/IntegrityCheck/CheckerTest.php b/tests/lib/IntegrityCheck/CheckerTest.php
index 454f1013c8ec..652b53c16f6b 100644
--- a/tests/lib/IntegrityCheck/CheckerTest.php
+++ b/tests/lib/IntegrityCheck/CheckerTest.php
@@ -138,20 +138,42 @@ public function testWriteAppSignature() {
 		$this->checker->writeAppSignature(\OC::$SERVERROOT . '/tests/data/integritycheck/app/', $x509, $rsa);
 	}
 
+	public function testIgnoredAppSignatureWithoutSignatureData() {
+		$this->environmentHelper
+			->expects($this->once())
+			->method('getChannel')
+			->will($this->returnValue('stable'));
+		$configMap = [
+			['integrity.check.disabled', false, false],
+			['integrity.ignore.missing.app.signature', [], ['SomeApp']]
+		];
+		$this->config
+			->expects($this->any())
+			->method('getSystemValue')
+			->will($this->returnValueMap($configMap));
+
+		$expected = [];
+		$this->assertSame($expected, $this->checker->verifyAppSignature('SomeApp'));
+	}
+
+
 	public function testVerifyAppSignatureWithoutSignatureData() {
 		$this->environmentHelper
 				->expects($this->once())
 				->method('getChannel')
 				->will($this->returnValue('stable'));
+		$configMap = [
+			['integrity.check.disabled', false, false],
+			['integrity.ignore.missing.app.signature', [], []]
+		];
 		$this->config
-				->expects($this->any())
-				->method('getSystemValue')
-				->with('integrity.check.disabled', false)
-				->will($this->returnValue(false));
+			->expects($this->any())
+			->method('getSystemValue')
+			->will($this->returnValueMap($configMap));
 
 		$expected = [
 			'EXCEPTION' => [
-					'class' => 'OC\IntegrityCheck\Exceptions\InvalidSignatureException',
+					'class' => 'OC\IntegrityCheck\Exceptions\MissingSignatureException',
 					'message' => 'Signature data not found.',
 			],
 		];
@@ -626,7 +648,7 @@ public function testVerifyCoreSignatureWithoutSignatureData() {
 
 		$expected = [
 			'EXCEPTION' => [
-				'class' => 'OC\\IntegrityCheck\\Exceptions\\InvalidSignatureException',
+				'class' => 'OC\\IntegrityCheck\\Exceptions\\MissingSignatureException',
 				'message' => 'Signature data not found.',
 			],
 		];