diff --git a/apps/dav/lib/CalDAV/Calendar.php b/apps/dav/lib/CalDAV/Calendar.php
index a07bbe9321..e80bffdb9d 100644
--- a/apps/dav/lib/CalDAV/Calendar.php
+++ b/apps/dav/lib/CalDAV/Calendar.php
@@ -139,6 +139,10 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IShareable {
 			];
 		}
 
+		if (!$this->isShared()) {
+			return $acl;
+		}
+
 		if ($this->getOwner() !== parent::getOwner()) {
 			$acl[] =  [
 					'privilege' => '{DAV:}read',
@@ -168,14 +172,9 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IShareable {
 		}
 
 		$acl = $this->caldavBackend->applyShareAcl($this->getResourceId(), $acl);
-
-		if (!$this->isShared()) {
-			return $acl;
-		}
-
 		$allowedPrincipals = [$this->getOwner(), parent::getOwner(), 'principals/system/public'];
 		return array_filter($acl, function($rule) use ($allowedPrincipals) {
-			return in_array($rule['principal'], $allowedPrincipals);
+			return \in_array($rule['principal'], $allowedPrincipals, true);
 		});
 	}
 
diff --git a/apps/dav/lib/CardDAV/AddressBook.php b/apps/dav/lib/CardDAV/AddressBook.php
index 7120231987..30ce0a3253 100644
--- a/apps/dav/lib/CardDAV/AddressBook.php
+++ b/apps/dav/lib/CardDAV/AddressBook.php
@@ -105,12 +105,17 @@ class AddressBook extends \Sabre\CardDAV\AddressBook implements IShareable {
 				'privilege' => '{DAV:}read',
 				'principal' => $this->getOwner(),
 				'protected' => true,
-			]];
-		$acl[] = [
+			],[
 				'privilege' => '{DAV:}write',
 				'principal' => $this->getOwner(),
 				'protected' => true,
-			];
+			]
+		];
+
+		if (!$this->isShared()) {
+			return $acl;
+		}
+
 		if ($this->getOwner() !== parent::getOwner()) {
 			$acl[] =  [
 					'privilege' => '{DAV:}read',
@@ -133,11 +138,11 @@ class AddressBook extends \Sabre\CardDAV\AddressBook implements IShareable {
 			];
 		}
 
-		if ($this->isShared()) {
-			return $acl;
-		}
-
-		return $this->carddavBackend->applyShareAcl($this->getResourceId(), $acl);
+		$acl = $this->carddavBackend->applyShareAcl($this->getResourceId(), $acl);
+		$allowedPrincipals = [$this->getOwner(), parent::getOwner(), 'principals/system/system'];
+		return array_filter($acl, function($rule) use ($allowedPrincipals) {
+			return \in_array($rule['principal'], $allowedPrincipals, true);
+		});
 	}
 
 	public function getChildACL() {
diff --git a/apps/dav/tests/travis/caldavtest/tests/CalDAV/sharing-calendars.xml b/apps/dav/tests/travis/caldavtest/tests/CalDAV/sharing-calendars.xml
index 334fa561ae..6c15a79322 100644
--- a/apps/dav/tests/travis/caldavtest/tests/CalDAV/sharing-calendars.xml
+++ b/apps/dav/tests/travis/caldavtest/tests/CalDAV/sharing-calendars.xml
@@ -73,7 +73,7 @@
 			<description>Shared calendar exists</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PROPFIND</method>
-				<ruri>$calendarhome1:/shared/</ruri>
+				<ruri>$calendarhome2:/shared_shared_by_user01/</ruri>
 				<header>
 					<name>Depth</name>
 					<value>0</value>
@@ -193,7 +193,7 @@
 			<description>Sharee creates event</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PUT</method>
-				<ruri>$calendarhome1:/shared/1.ics</ruri>
+				<ruri>$calendarhome2:/shared_shared_by_user01/1.ics</ruri>
 				<data>
 					<content-type>text/calendar; charset=utf-8</content-type>
 					<filepath>Resource/CalDAV/sharing/calendars/read-write/5.ics</filepath>
@@ -235,7 +235,7 @@
 			<description>Sharee sees changed event</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>GET</method>
-				<ruri>$calendarhome1:/shared/1.ics</ruri>
+				<ruri>$calendarhome2:/shared_shared_by_user01/1.ics</ruri>
 				<verify>
 					<callback>calendarDataMatch</callback>
 					<arg>
@@ -263,7 +263,7 @@
 			<description>Sharee sees new event</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>GET</method>
-				<ruri>$calendarhome1:/shared/2.ics</ruri>
+				<ruri>$calendarhome2:/shared_shared_by_user01/2.ics</ruri>
 				<verify>
 					<callback>calendarDataMatch</callback>
 					<arg>
@@ -277,7 +277,7 @@
 			<description>Sharee changes event</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PUT</method>
-				<ruri>$calendarhome1:/shared/2.ics</ruri>
+				<ruri>$calendarhome2:/shared_shared_by_user01/2.ics</ruri>
 				<data>
 					<content-type>text/calendar; charset=utf-8</content-type>
 					<filepath>Resource/CalDAV/sharing/calendars/read-write/8.ics</filepath>
diff --git a/apps/dav/tests/travis/caldavtest/tests/CardDAV/sharing-addressbooks.xml b/apps/dav/tests/travis/caldavtest/tests/CardDAV/sharing-addressbooks.xml
index 84ee626501..99e40f5c68 100644
--- a/apps/dav/tests/travis/caldavtest/tests/CardDAV/sharing-addressbooks.xml
+++ b/apps/dav/tests/travis/caldavtest/tests/CardDAV/sharing-addressbooks.xml
@@ -17,7 +17,7 @@
 			<description>POST invitation</description>
 			<request>
 				<method>POST</method>
-				<ruri>$addressbookpath1:</ruri>
+				<ruri>$addressbookhome1:/addressbook/</ruri>
 				<data>
 					<content-type>text/xml; charset=utf-8</content-type>
 					<filepath>Resource/CardDAV/sharing/read-write/1.xml</filepath>
@@ -31,7 +31,7 @@
 			<description>Shared addressbook exists</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PROPFIND</method>
-				<ruri>$addressbookpath1:/</ruri>
+				<ruri>$addressbookhome2:/addressbook_shared_by_user01/</ruri>
 				<header>
 					<name>Depth</name>
 					<value>0</value>
@@ -62,7 +62,7 @@
 		</test>
 
 		<test name='4a'>
-			<description>Shared calendar exists Depth:1</description>
+			<description>Shared addressbook exists Depth:1</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PROPFIND</method>
 				<ruri>$addressbookhome2:/</ruri>
@@ -100,7 +100,7 @@
 		</test>
 
 		<test name='5'>
-			<description>Original calendar unchanged</description>
+			<description>Original addressbook unchanged</description>
 			<request>
 				<method>PROPFIND</method>
 				<ruri>$addressbookpath1:</ruri>
@@ -126,7 +126,7 @@
 			<description>Sharee creates contact</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PUT</method>
-				<ruri>$addressbookpath1:/1.vcf</ruri>
+				<ruri>$addressbookhome2:/addressbook_shared_by_user01/1.vcf</ruri>
 				<data>
 					<content-type>text/vcard; charset=utf-8</content-type>
 					<filepath>Resource/CardDAV/sharing/read-write/6.vcf</filepath>
@@ -171,7 +171,7 @@
 			<description>Sharee sees changed contact</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>GET</method>
-				<ruri>$addressbookpath1:/1.vcf</ruri>
+				<ruri>$addressbookhome2:/addressbook_shared_by_user01/1.vcf</ruri>
 				<verify>
 					<callback>addressDataMatch</callback>
 					<arg>
@@ -183,7 +183,7 @@
 		</test>
 
 		<test name='10'>
-			<description>Sharer creates event</description>
+			<description>Sharer creates contact</description>
 			<request>
 				<method>PUT</method>
 				<ruri>$addressbookpath1:/2.vcf</ruri>
@@ -197,10 +197,10 @@
 			</request>
 		</test>
 		<test name='11'>
-			<description>Sharee sees new event</description>
+			<description>Sharee sees new contact</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>GET</method>
-				<ruri>$addressbookpath1:/2.vcf</ruri>
+				<ruri>$addressbookhome2:/addressbook_shared_by_user01/2.vcf</ruri>
 				<verify>
 					<callback>addressDataMatch</callback>
 					<arg>
@@ -211,10 +211,10 @@
 			</request>
 		</test>
 		<test name='12'>
-			<description>Sharee changes event</description>
+			<description>Sharee changes contact</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PUT</method>
-				<ruri>$addressbookpath1:/2.vcf</ruri>
+				<ruri>$addressbookhome2:/addressbook_shared_by_user01/2.vcf</ruri>
 				<data>
 					<content-type>text/vcard; charset=utf-8</content-type>
 					<filepath>Resource/CardDAV/sharing/read-write/9.vcf</filepath>
@@ -225,7 +225,7 @@
 			</request>
 		</test>
 		<test name='13'>
-			<description>Sharer sees changed event</description>
+			<description>Sharer sees changed contact</description>
 			<request>
 				<method>GET</method>
 				<ruri>$addressbookpath1:/2.vcf</ruri>
@@ -281,7 +281,7 @@
 				</verify>			</request>
 		</test>
 		<test name='16'>
-			<description>Shared calendar no longer exists Depth:1</description>
+			<description>Shared addressbook no longer exists Depth:1</description>
 			<request user="$userid2:" pswd="$pswd2:">
 				<method>PROPFIND</method>
 				<ruri>$addressbookhome2:</ruri>