diff --git a/includes/orphaned_objects.inc b/includes/orphaned_objects.inc
index 7393971d..4941bab5 100644
--- a/includes/orphaned_objects.inc
+++ b/includes/orphaned_objects.inc
@@ -170,6 +170,8 @@ WHERE {
 } ORDER BY ?object
 EOQ;
   $parent_relationships = module_invoke_all('islandora_solution_pack_child_relationships', 'all');
+  $parent_relationships['prefix'] = array_unique($parent_relationships['prefix']);
+  $parent_relationships['predicate'] = array_unique($parent_relationships['predicate']);
   if (count($parent_relationships['predicate']) == 0) {
     // No predicates to search for. Exit early.
     return array();