diff --git a/apps/files_sharing/api/share20ocs.php b/apps/files_sharing/api/share20ocs.php
index 48aca9b9c1b714db3fa0ba9e37d8a8f794c716b4..1d84aefa764615af18f72f0c357105b48ddde7dc 100644
--- a/apps/files_sharing/api/share20ocs.php
+++ b/apps/files_sharing/api/share20ocs.php
@@ -464,10 +464,41 @@ class Share20OCS {
 		 * expirationdate, password and publicUpload only make sense for link shares
 		 */
 		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
-			if ($password === null && $publicUpload === null && $expireDate === null) {
+			if ($permissions === null && $password === null && $publicUpload === null && $expireDate === null) {
 				return new \OC_OCS_Result(null, 400, 'Wrong or no update parameter given');
 			}
 
+			$newPermissions = null;
+			if ($publicUpload === 'true') {
+				$newPermissions = \OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE;
+			} else if ($publicUpload === 'false') {
+				$newPermissions = \OCP\Constants::PERMISSION_READ;
+			}
+
+			if ($permissions !== null) {
+				$newPermissions = (int)$permissions;
+			}
+
+			if ($newPermissions !== null &&
+				$newPermissions !== \OCP\Constants::PERMISSION_READ &&
+				$newPermissions !== (\OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE)) {
+				return new \OC_OCS_Result(null, 400, 'can\'t change permission for public link share');
+			}
+
+			if ($newPermissions === (\OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE)) {
+				if (!$this->shareManager->shareApiLinkAllowPublicUpload()) {
+					return new \OC_OCS_Result(null, 403, 'public upload disabled by the administrator');
+				}
+
+				if (!($share->getPath() instanceof \OCP\Files\Folder)) {
+					return new \OC_OCS_Result(null, 400, "public upload is only possible for public shared folders");
+				}
+			}
+
+			if ($newPermissions !== null) {
+				$share->setPermissions($newPermissions);
+			}
+
 			if ($expireDate === '') {
 				$share->setExpirationDate(null);
 			} else if ($expireDate !== null) {
@@ -485,20 +516,8 @@ class Share20OCS {
 				$share->setPassword($password);
 			}
 
-			if ($publicUpload === 'true') {
-				if(!$this->shareManager->shareApiLinkAllowPublicUpload()) {
-					return new \OC_OCS_Result(null, 403, "public upload disabled by the administrator");
-				}
-
-				if (!($share->getPath() instanceof \OCP\Files\Folder)) {
-					return new \OC_OCS_Result(null, 400, "public upload is only possible for public shared folders");
-				}
-
-				$share->setPermissions(\OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE);
-			} else if ($publicUpload === 'false') {
-				$share->setPermissions(\OCP\Constants::PERMISSION_READ);
-			}
 		} else {
+			// For other shares only permissions is valid.
 			if ($permissions === null) {
 				return new \OC_OCS_Result(null, 400, 'Wrong or no update parameter given');
 			} else {
@@ -518,6 +537,14 @@ class Share20OCS {
 		return new \OC_OCS_Result($this->formatShare($share));
 	}
 
+	public function validatePermissions($permissions) {
+		if ($permissions < 0 || $permissions > \OCP\Constants::PERMISSION_ALL) {
+			return false;
+		}
+
+
+	}
+
 	/**
 	 * @param IShare $share
 	 * @return bool
diff --git a/apps/files_sharing/tests/api/share20ocstest.php b/apps/files_sharing/tests/api/share20ocstest.php
index b440ba96e0424733401ea375a82ee2569dbc62f1..18f05b7867d8ef7feb6fd647420ca0485aaafde4 100644
--- a/apps/files_sharing/tests/api/share20ocstest.php
+++ b/apps/files_sharing/tests/api/share20ocstest.php
@@ -1252,6 +1252,78 @@ class Share20OCSTest extends \Test\TestCase {
 		$this->assertEquals($expected->getData(), $result->getData());
 	}
 
+	public function testUpdateLinkSharePermissions() {
+		$ocs = $this->mockFormatShare();
+
+		$date = new \DateTime('2000-01-01');
+
+		$folder = $this->getMock('\OCP\Files\Folder');
+
+		$share = \OC::$server->getShareManager()->newShare();
+		$share->setPermissions(\OCP\Constants::PERMISSION_ALL)
+			->setSharedBy($this->currentUser)
+			->setShareType(\OCP\Share::SHARE_TYPE_LINK)
+			->setPassword('password')
+			->setExpirationDate($date)
+			->setPermissions(\OCP\Constants::PERMISSION_ALL)
+			->setPath($folder);
+
+		$this->request
+			->method('getParam')
+			->will($this->returnValueMap([
+				['permissions', null, '7'],
+			]));
+
+		$this->shareManager->method('getShareById')->with('ocinternal:42')->willReturn($share);
+		$this->shareManager->method('shareApiLinkAllowPublicUpload')->willReturn(true);
+
+		$this->shareManager->expects($this->once())->method('updateShare')->with(
+			$this->callback(function (IShare $share) use ($date) {
+				return $share->getPermissions() === \OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_DELETE &&
+				$share->getPassword() === 'password' &&
+				$share->getExpirationDate() === $date;
+			})
+		);
+
+		$expected = new \OC_OCS_Result(null);
+		$result = $ocs->updateShare(42);
+
+		$this->assertEquals($expected->getMeta(), $result->getMeta());
+		$this->assertEquals($expected->getData(), $result->getData());
+	}
+
+	public function testUpdateLinkShareInvalidPermissions() {
+		$ocs = $this->mockFormatShare();
+
+		$date = new \DateTime('2000-01-01');
+
+		$folder = $this->getMock('\OCP\Files\Folder');
+
+		$share = \OC::$server->getShareManager()->newShare();
+		$share->setPermissions(\OCP\Constants::PERMISSION_ALL)
+			->setSharedBy($this->currentUser)
+			->setShareType(\OCP\Share::SHARE_TYPE_LINK)
+			->setPassword('password')
+			->setExpirationDate($date)
+			->setPermissions(\OCP\Constants::PERMISSION_ALL)
+			->setPath($folder);
+
+		$this->request
+			->method('getParam')
+			->will($this->returnValueMap([
+				['permissions', null, '31'],
+			]));
+
+		$this->shareManager->method('getShareById')->with('ocinternal:42')->willReturn($share);
+		$this->shareManager->method('shareApiLinkAllowPublicUpload')->willReturn(true);
+
+		$expected = new \OC_OCS_Result(null, 400, 'can\'t change permission for public link share');
+		$result = $ocs->updateShare(42);
+
+		$this->assertEquals($expected->getMeta(), $result->getMeta());
+		$this->assertEquals($expected->getData(), $result->getData());
+	}
+
 	public function testUpdateOtherPermissions() {
 		$ocs = $this->mockFormatShare();