diff --git a/src/library/relation_manager.cpp b/src/library/relation_manager.cpp
index 9b13d15a5..8dacca1e4 100644
--- a/src/library/relation_manager.cpp
+++ b/src/library/relation_manager.cpp
@@ -85,6 +85,7 @@ struct rel_state {
                     throw_invalid_relation(rop);
             }
             type = binding_body(type);
+            i++;
         }
         if (lhs_pos && rhs_pos) {
             m_rop_table.insert(rop, relation_info(i, *lhs_pos, *rhs_pos));