Fix a bug introduced in #8783

diff --git a/source/distributed/tria_base.cc b/source/distributed/tria_base.cc
index e2c91bfa8d6dd5a082d3abbd73aa2064fc6bc49f..bad673e21e81686fecf05d5f40bb49a9158887c5 100644 (file)
--- a/source/distributed/tria_base.cc
+++ b/source/distributed/tria_base.cc
@@ -394,6 +394,9 @@ namespace parallel
       // loop over all periodic face pairs
       for (const auto &pair : this->get_periodic_face_map())
         {
+          if (pair.first.first->level() != pair.second.first.first->level())
+            continue;
+
           const auto face_a = pair.first.first->face(pair.first.second);
           const auto face_b =
             pair.second.first.first->face(pair.second.first.second);