diff --git a/app/src/main/java/com/etesync/syncadapter/resource/LocalGroup.kt b/app/src/main/java/com/etesync/syncadapter/resource/LocalGroup.kt
index 99e6fb18..2282e7de 100644
--- a/app/src/main/java/com/etesync/syncadapter/resource/LocalGroup.kt
+++ b/app/src/main/java/com/etesync/syncadapter/resource/LocalGroup.kt
@@ -63,8 +63,9 @@ class LocalGroup : AndroidGroup, LocalAddress {
                     // insert memberships
                     val membersIds = members.map {uid ->
                         Constants.log.fine("Assigning member: $uid")
-                        (addressBook.findByUid(uid) as LocalContact).id!!
-                    }
+                        val contact = addressBook.findByUid(uid) as LocalContact?
+                        if (contact != null) contact.id else null
+                    }.filterNotNull()
 
                     val group = addressBook.findGroupById(id)
                     group.setMembers(batch, membersIds)