diff --git a/app/src/main/java/at/bitfire/davdroid/DavService.kt b/app/src/main/java/at/bitfire/davdroid/DavService.kt
index e246ec4fa..8e1f33ea0 100644
--- a/app/src/main/java/at/bitfire/davdroid/DavService.kt
+++ b/app/src/main/java/at/bitfire/davdroid/DavService.kt
@@ -16,7 +16,6 @@ import android.os.Binder
 import android.os.Bundle
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
-import androidx.room.Transaction
 import at.bitfire.dav4jvm.DavResource
 import at.bitfire.dav4jvm.Response
 import at.bitfire.dav4jvm.UrlUtils
@@ -36,6 +35,7 @@ import okhttp3.OkHttpClient
 import java.lang.ref.WeakReference
 import java.util.*
 import java.util.logging.Level
+import kotlin.collections.*
 
 class DavService: android.app.Service() {
 
@@ -76,7 +76,10 @@ class DavService: android.app.Service() {
                             listener.get()?.onDavRefreshStatusChanged(id, true)
                         }
                         CoroutineScope(Dispatchers.IO).launch {
-                            refreshCollections(id)
+                            val db = AppDatabase.getInstance(this@DavService)
+                            db.runInTransaction {
+                                refreshCollections(db, id)
+                            }
                         }
                     }
 
@@ -141,8 +144,7 @@ class DavService: android.app.Service() {
         ContentResolver.requestSync(account, authority, extras)
     }
 
-    private fun refreshCollections(serviceId: Long) {
-        val db = AppDatabase.getInstance(this)
+    private fun refreshCollections(db: AppDatabase, serviceId: Long) {
         val homeSetDao = db.homeSetDao()
         val collectionDao = db.collectionDao()
 
@@ -249,7 +251,6 @@ class DavService: android.app.Service() {
                 queryHomeSets(client, resource, false)
         }
 
-        @Transaction
         fun saveHomesets() {
             DaoTools(homeSetDao).syncAll(
                     homeSetDao.getByService(serviceId),
@@ -257,7 +258,6 @@ class DavService: android.app.Service() {
                     { it.url })
         }
 
-        @Transaction
         fun saveCollections() {
             DaoTools(collectionDao).syncAll(
                     collectionDao.getByService(serviceId),
@@ -285,7 +285,6 @@ class DavService: android.app.Service() {
                     Logger.log.fine("Querying principal $principalUrl for home sets")
                     queryHomeSets(httpClient, principalUrl)
                 }
-                saveHomesets()
 
                 // now refresh homesets and their member collections
                 val itHomeSets = homeSets.iterator()
@@ -307,7 +306,7 @@ class DavService: android.app.Service() {
                             // in any case, check whether the response is about a useable collection
                             val info = Collection.fromDavResponse(response) ?: return@propfind
                             info.serviceId = serviceId
-                            info.homeSetId = homeSet.id
+                            info.refHomeSet = homeSet
                             info.confirmed = true
                             info.owner = response[Owner::class.java]?.href?.let { response.href.resolve(it) }
                             Logger.log.log(Level.FINE, "Found collection", info)
@@ -348,13 +347,21 @@ class DavService: android.app.Service() {
                             }
                         } catch(e: HttpException) {
                             if (e.code in arrayOf(403, 404, 410))
-                            // delete collection only if it was not accessible (40x)
+                                // delete collection only if it was not accessible (40x)
                                 itCollections.remove()
                             else
                                 throw e
                         }
                 }
             }
+
+            saveHomesets()
+
+            // use refHomeSet (if available) to determine homeset ID
+            for (collection in collections.values)
+                collection.refHomeSet?.let { homeSet ->
+                    collection.homeSetId = homeSet.id
+                }
             saveCollections()
 
         } catch(e: InvalidAccountException) {
diff --git a/app/src/main/java/at/bitfire/davdroid/model/Collection.kt b/app/src/main/java/at/bitfire/davdroid/model/Collection.kt
index 8ffd1802d..e44d99484 100644
--- a/app/src/main/java/at/bitfire/davdroid/model/Collection.kt
+++ b/app/src/main/java/at/bitfire/davdroid/model/Collection.kt
@@ -60,6 +60,10 @@ data class Collection(
 
 ): IdEntity() {
 
+    @Ignore
+    var refHomeSet: HomeSet? = null
+
+
     companion object {
 
         const val TYPE_ADDRESSBOOK = "ADDRESS_BOOK"
diff --git a/app/src/main/java/at/bitfire/davdroid/model/CollectionDao.kt b/app/src/main/java/at/bitfire/davdroid/model/CollectionDao.kt
index b04da3e72..49a55eac1 100644
--- a/app/src/main/java/at/bitfire/davdroid/model/CollectionDao.kt
+++ b/app/src/main/java/at/bitfire/davdroid/model/CollectionDao.kt
@@ -16,7 +16,7 @@ interface CollectionDao: SyncableDao<Collection> {
     @Query("SELECT * FROM collection WHERE serviceId=:serviceId")
     fun getByService(serviceId: Long): List<Collection>
 
-    @Query("SELECT * FROM collection WHERE serviceId=:serviceId AND type=:type")
+    @Query("SELECT * FROM collection WHERE serviceId=:serviceId AND type=:type ORDER BY displayName, url")
     fun getByServiceAndType(serviceId: Long, type: String): List<Collection>
 
     /**
@@ -25,10 +25,10 @@ interface CollectionDao: SyncableDao<Collection> {
      *   - have supportsVEVENT = supportsVTODO = null (= address books)
      */
     @Query("SELECT * FROM collection WHERE serviceId=:serviceId AND type=:type " +
-            "AND (supportsVTODO OR supportsVEVENT OR (supportsVEVENT IS NULL AND supportsVTODO IS NULL))")
+            "AND (supportsVTODO OR supportsVEVENT OR (supportsVEVENT IS NULL AND supportsVTODO IS NULL)) ORDER BY displayName, URL")
     fun pageByServiceAndType(serviceId: Long, type: String): DataSource.Factory<Int, Collection>
 
-    @Query("SELECT * FROM collection WHERE serviceId=:serviceId AND sync ORDER BY displayName, url")
+    @Query("SELECT * FROM collection WHERE serviceId=:serviceId AND sync")
     fun getByServiceAndSync(serviceId: Long): List<Collection>
 
     @Query("SELECT collection.* FROM collection, homeset WHERE collection.serviceId=:serviceId AND type=:type AND homeSetId=homeset.id AND homeset.personal ORDER BY collection.displayName, collection.url")