diff --git a/passes/techmap/abc9.cc b/passes/techmap/abc9.cc
index caaff9256..fbf3a47ee 100644
--- a/passes/techmap/abc9.cc
+++ b/passes/techmap/abc9.cc
@@ -1405,6 +1405,9 @@ struct Abc9Pass : public Pass {
 				continue;
 			}
 
+			if (mod->attributes.count("\\abc_box_id"))
+				continue;
+
 			assign_map.set(mod);
 			signal_init.clear();