diff --git a/netclass.cc b/netclass.cc
index 278fceb43..60f5f37ff 100644
--- a/netclass.cc
+++ b/netclass.cc
@@ -136,7 +136,7 @@ bool netclass_t::get_prop_initialized(size_t idx) const
       if (idx < super_size)
 	    return super_->get_prop_initialized(idx);
       else
-	    return property_table_[idx].initialized_flag;
+	    return property_table_[idx-super_size].initialized_flag;
 }
 
 void netclass_t::set_prop_initialized(size_t idx) const