diff --git a/src/dynamic_selection_list.cc b/src/dynamic_selection_list.cc
index d3d3497c..3de8c80c 100644
--- a/src/dynamic_selection_list.cc
+++ b/src/dynamic_selection_list.cc
@@ -28,6 +28,8 @@ void DynamicSelectionList::check_invariant() const
         auto& sel = (*this)[i];
         kak_assert(buffer.is_valid(sel.first()));
         kak_assert(buffer.is_valid(sel.last()));
+        kak_assert(not buffer.is_end(sel.first()));
+        kak_assert(not buffer.is_end(sel.last()));
         kak_assert(utf8::is_character_start(sel.first()));
         kak_assert(utf8::is_character_start(sel.last()));
     }