diff --git a/app/src/main/java/org/tasks/Tasks.kt b/app/src/main/java/org/tasks/Tasks.kt
index 4486ce7a4..21fe1e02c 100644
--- a/app/src/main/java/org/tasks/Tasks.kt
+++ b/app/src/main/java/org/tasks/Tasks.kt
@@ -19,6 +19,8 @@ import kotlinx.coroutines.launch
 import org.tasks.billing.BillingClient
 import org.tasks.billing.Inventory
 import org.tasks.caldav.property.Invite
+import org.tasks.caldav.property.OCOwnerPrincipal
+import org.tasks.caldav.property.PropertyUtils.register
 import org.tasks.caldav.property.ShareAccess
 import org.tasks.files.FileHelper
 import org.tasks.injection.InjectingJobIntentService
@@ -93,10 +95,11 @@ class Tasks : Application(), Configuration.Provider {
         FileHelper.delete(context, preferences.cacheDirectory)
         billingClient.get().queryPurchases()
         appWidgetManager.get().reconfigureWidgets()
-        PropertyRegistry.register(listOf(
+        PropertyRegistry.register(
                 ShareAccess.Factory(),
-                Invite.Factory()
-        ))
+                Invite.Factory(),
+                OCOwnerPrincipal.Factory(),
+        )
     }
 
     override fun getWorkManagerConfiguration(): Configuration = Configuration.Builder()
diff --git a/app/src/main/java/org/tasks/caldav/CaldavClient.kt b/app/src/main/java/org/tasks/caldav/CaldavClient.kt
index 495a974c2..75dc00ee4 100644
--- a/app/src/main/java/org/tasks/caldav/CaldavClient.kt
+++ b/app/src/main/java/org/tasks/caldav/CaldavClient.kt
@@ -20,6 +20,7 @@ import okhttp3.OkHttpClient
 import org.tasks.R
 import org.tasks.Strings.isNullOrEmpty
 import org.tasks.caldav.property.Invite
+import org.tasks.caldav.property.OCOwnerPrincipal
 import org.tasks.caldav.property.ShareAccess
 import org.tasks.data.CaldavAccount
 import org.tasks.ui.DisplayableException
@@ -219,7 +220,8 @@ open class CaldavClient(
                 CalendarColor.NAME,
                 SyncToken.NAME,
                 ShareAccess.NAME,
-                Invite.NAME
+                Invite.NAME,
+                OCOwnerPrincipal.NAME,
         )
 
         private suspend fun DavResource.propfind(
diff --git a/app/src/main/java/org/tasks/caldav/property/OCOwnerPrincipal.kt b/app/src/main/java/org/tasks/caldav/property/OCOwnerPrincipal.kt
new file mode 100644
index 000000000..5a3c158ab
--- /dev/null
+++ b/app/src/main/java/org/tasks/caldav/property/OCOwnerPrincipal.kt
@@ -0,0 +1,19 @@
+package org.tasks.caldav.property
+
+import at.bitfire.dav4jvm.Property
+import at.bitfire.dav4jvm.PropertyFactory
+import at.bitfire.dav4jvm.XmlUtils
+import org.xmlpull.v1.XmlPullParser
+
+data class OCOwnerPrincipal(val owner: String): Property {
+    companion object {
+        @JvmField
+        val NAME = Property.Name(PropertyUtils.NS_OWNCLOUD, "owner-principal")
+    }
+
+    class Factory: PropertyFactory {
+        override fun getName() = NAME
+        override fun create(parser: XmlPullParser): OCOwnerPrincipal? =
+                XmlUtils.readText(parser)?.let { OCOwnerPrincipal(it) }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/tasks/caldav/property/PropertyUtils.kt b/app/src/main/java/org/tasks/caldav/property/PropertyUtils.kt
new file mode 100644
index 000000000..67e9a837a
--- /dev/null
+++ b/app/src/main/java/org/tasks/caldav/property/PropertyUtils.kt
@@ -0,0 +1,10 @@
+package org.tasks.caldav.property
+
+import at.bitfire.dav4jvm.PropertyFactory
+import at.bitfire.dav4jvm.PropertyRegistry
+
+object PropertyUtils {
+    const val NS_OWNCLOUD = "http://owncloud.org/ns"
+
+    fun PropertyRegistry.register(vararg factories: PropertyFactory) = register(factories.toList())
+}
\ No newline at end of file
diff --git a/app/src/test/java/org/tasks/caldav/property/InviteTest.kt b/app/src/test/java/org/tasks/caldav/property/InviteTest.kt
index b69b15c33..8cfee4281 100644
--- a/app/src/test/java/org/tasks/caldav/property/InviteTest.kt
+++ b/app/src/test/java/org/tasks/caldav/property/InviteTest.kt
@@ -4,44 +4,33 @@ import at.bitfire.dav4jvm.PropertyRegistry
 import org.junit.Assert.*
 import org.junit.Before
 import org.junit.Test
-import org.tasks.caldav.property.PropertyUtils.toProperty
+import org.tasks.caldav.property.PropertyUtils.register
 import org.tasks.caldav.property.ShareAccess.Companion.SHARED_OWNER
+import org.tasks.caldav.property.TestPropertyUtils.toProperty
 
 class InviteTest {
     @Before
     fun setUp() {
-        PropertyRegistry.register(listOf(
-                ShareAccess.Factory(),
-                Invite.Factory()
-        ))
+        PropertyRegistry.register(ShareAccess.Factory(), Invite.Factory())
     }
 
     @Test
-    fun emptyInvite() {
-        val invite: Invite = "<d:invite />".toProperty()
+    fun emptyInvite() = assertTrue("<d:invite />".toProperty<Invite>().sharees.isEmpty())
 
-        assertTrue(invite.sharees.isEmpty())
-    }
+    @Test
+    fun shareeAccess() = assertEquals(ShareAccess(SHARED_OWNER), sharee(SHARE_OWNER).access)
 
     @Test
-    fun shareeAccess() {
-        assertEquals(ShareAccess(SHARED_OWNER), sharee(SHARE_OWNER).access)
-    }
+    fun shareeHref() = assertEquals("/principals/102967489186752069531", sharee(SHARE_OWNER).href)
 
     @Test
-    fun shareeHref() {
-        assertEquals("/principals/102967489186752069531", sharee(SHARE_OWNER).href)
-    }
+    fun inviteStatus() = assertEquals(Sharee.INVITE_ACCEPTED, sharee(SHARE_OWNER).response)
 
     @Test
-    fun inviteStatus() {
-        assertEquals(Sharee.INVITE_ACCEPTED, sharee(SHARE_OWNER).response)
-    }
+    fun noComment() = assertNull(sharee(SHARE_OWNER).comment)
 
     @Test
-    fun noComment() {
-        assertNull(sharee(SHARE_OWNER).comment)
-    }
+    fun noProperties() = assertTrue(sharee(SHARE_OWNER).properties.isEmpty())
 
     private fun sharee(xml: String): Sharee = xml.toProperty<Invite>().sharees.first()
 
diff --git a/app/src/test/java/org/tasks/caldav/property/OCOwnerPrincipalTest.kt b/app/src/test/java/org/tasks/caldav/property/OCOwnerPrincipalTest.kt
new file mode 100644
index 000000000..e0b3d90a5
--- /dev/null
+++ b/app/src/test/java/org/tasks/caldav/property/OCOwnerPrincipalTest.kt
@@ -0,0 +1,22 @@
+package org.tasks.caldav.property
+
+import at.bitfire.dav4jvm.PropertyRegistry
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import org.tasks.caldav.property.TestPropertyUtils.toProperty
+
+class OCOwnerPrincipalTest {
+    @Before
+    fun setUp() {
+        PropertyRegistry.register(OCOwnerPrincipal.Factory())
+    }
+
+    @Test
+    fun ownerPrincipal() {
+        val owner = "<oc:owner-principal>principals/users/test</oc:owner-principal>"
+                .toProperty<OCOwnerPrincipal>("oc='${PropertyUtils.NS_OWNCLOUD}'")
+
+        assertEquals("principals/users/test", owner.owner)
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/org/tasks/caldav/property/ShareAccessTest.kt b/app/src/test/java/org/tasks/caldav/property/ShareAccessTest.kt
index 6828e4493..ee56c18b8 100644
--- a/app/src/test/java/org/tasks/caldav/property/ShareAccessTest.kt
+++ b/app/src/test/java/org/tasks/caldav/property/ShareAccessTest.kt
@@ -4,7 +4,7 @@ import at.bitfire.dav4jvm.PropertyRegistry
 import org.junit.Assert.assertEquals
 import org.junit.Before
 import org.junit.Test
-import org.tasks.caldav.property.PropertyUtils.toProperty
+import org.tasks.caldav.property.TestPropertyUtils.toProperty
 import org.tasks.caldav.property.ShareAccess.Companion.SHARED_OWNER
 
 class ShareAccessTest {
diff --git a/app/src/test/java/org/tasks/caldav/property/PropertyUtils.kt b/app/src/test/java/org/tasks/caldav/property/TestPropertyUtils.kt
similarity index 77%
rename from app/src/test/java/org/tasks/caldav/property/PropertyUtils.kt
rename to app/src/test/java/org/tasks/caldav/property/TestPropertyUtils.kt
index d798b40f9..ce8375d4e 100644
--- a/app/src/test/java/org/tasks/caldav/property/PropertyUtils.kt
+++ b/app/src/test/java/org/tasks/caldav/property/TestPropertyUtils.kt
@@ -4,9 +4,9 @@ import at.bitfire.dav4jvm.Property
 import at.bitfire.dav4jvm.XmlUtils
 import java.io.StringReader
 
-object PropertyUtils {
-    fun <T: Property> String.toProperty(): T =
-            toProperties()
+object TestPropertyUtils {
+    fun <T: Property> String.toProperty(ns: String = """d="DAV:""""): T =
+            toProperties(ns)
                     .apply { if (this.size != 1) throw IllegalStateException("${this.size} items") }
                     .first()
                     .let {
@@ -14,12 +14,12 @@ object PropertyUtils {
                         it as T
                     }
 
-    fun String.toProperties(): List<Property> =
+    fun String.toProperties(ns: String = """d="DAV:""""): List<Property> =
             XmlUtils.newPullParser()
                     .apply {
                         setInput(
                                 StringReader("""
-                                    <test xmlns:d="DAV:">
+                                    <test xmlns:$ns>
                                         ${this@toProperties}
                                     </test>
                                     """.trimIndent()