diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index 790ba52a3..f732b56b0 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -1565,13 +1565,21 @@ void RTLIL::Module::remove(const pool<RTLIL::Wire*> &wires)
 
 void RTLIL::Module::remove(RTLIL::Cell *cell)
 {
+	auto it = cells_.find(cell->name);
+	log_assert(it != cells_.end());
+	remove(it);
+}
+
+dict<RTLIL::IdString, RTLIL::Cell*>::iterator RTLIL::Module::remove(dict<RTLIL::IdString, RTLIL::Cell*>::iterator it)
+{
+	RTLIL::Cell *cell = it->second;
 	while (!cell->connections_.empty())
 		cell->unsetPort(cell->connections_.begin()->first);
 
-	log_assert(cells_.count(cell->name) != 0);
 	log_assert(refcount_cells_ == 0);
-	cells_.erase(cell->name);
+	it = cells_.erase(it);
 	delete cell;
+	return it;
 }
 
 void RTLIL::Module::rename(RTLIL::Wire *wire, RTLIL::IdString new_name)
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index f4fcf5dcf..4a0f8b4f8 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -1040,6 +1040,7 @@ public:
 	// Removing wires is expensive. If you have to remove wires, remove them all at once.
 	void remove(const pool<RTLIL::Wire*> &wires);
 	void remove(RTLIL::Cell *cell);
+	dict<RTLIL::IdString, RTLIL::Cell*>::iterator remove(dict<RTLIL::IdString, RTLIL::Cell*>::iterator it);
 
 	void rename(RTLIL::Wire *wire, RTLIL::IdString new_name);
 	void rename(RTLIL::Cell *cell, RTLIL::IdString new_name);
diff --git a/passes/techmap/abc9.cc b/passes/techmap/abc9.cc
index 54aba3b18..9c4e6bb39 100644
--- a/passes/techmap/abc9.cc
+++ b/passes/techmap/abc9.cc
@@ -500,24 +500,6 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 			}
 		}
 
-		// Remove all AND, NOT, and ABC box instances
-		// in preparation for stitching mapped_mod in
-		dict<IdString, decltype(RTLIL::Cell::parameters)> erased_boxes;
-		for (auto it = module->cells_.begin(); it != module->cells_.end(); ) {
-			RTLIL::Cell* cell = it->second;
-			if (cell->type.in("$_AND_", "$_NOT_")) {
-				it = module->cells_.erase(it);
-				continue;
-			}
-			RTLIL::Module* box_module = design->module(cell->type);
-			if (box_module && box_module->attributes.count("\\abc_box_id")) {
-				erased_boxes.insert(std::make_pair(it->first, std::move(cell->parameters)));
-				it = module->cells_.erase(it);
-				continue;
-			}
-			++it;
-		}
-		// Do the same for module connections
 		for (auto &it : module->connections_) {
 			auto &signal = it.first;
 			auto bits = signal.bits();
@@ -527,6 +509,19 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 			signal = std::move(bits);
 		}
 
+		vector<RTLIL::Cell*> boxes;
+		for (auto it = module->cells_.begin(); it != module->cells_.end(); ) {
+			RTLIL::Cell* cell = it->second;
+			if (cell->type.in("$_AND_", "$_NOT_", "$__ABC_FF_")) {
+				it = module->remove(it);
+				continue;
+			}
+			RTLIL::Module* box_module = design->module(cell->type);
+			if (box_module && box_module->attributes.count("\\abc_box_id"))
+				boxes.emplace_back(it->second);
+			++it;
+		}
+
 		std::map<std::string, int> cell_stats;
 		for (auto c : mapped_mod->cells())
 		{
@@ -595,18 +590,21 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 					SigSpec my_a = module->wires_[remap_name(c->getPort("\\A").as_wire()->name)];
 					SigSpec my_y = module->wires_[remap_name(c->getPort("\\Y").as_wire()->name)];
 					module->connect(my_y, my_a);
+                                        if (markgroups) c->attributes["\\abcgroup"] = map_autoidx;
 					continue;
 				}
 			}
-			else {
-				auto it = erased_boxes.find(c->name);
-				log_assert(it != erased_boxes.end());
-				c->parameters = std::move(it->second);
-			}
 
-			RTLIL::Cell* cell = module->addCell(remap_name(c->name), c->type);
+			RTLIL::Cell *cell = module->addCell(remap_name(c->name), c->type);
 			if (markgroups) cell->attributes["\\abcgroup"] = map_autoidx;
-			cell->parameters = c->parameters;
+                        RTLIL::Cell *existing_cell = module->cell(c->name);
+                        if (existing_cell) {
+                                cell->parameters = std::move(existing_cell->parameters);
+                                cell->attributes = std::move(existing_cell->attributes);
+                        }
+                        else {
+                                cell->parameters = std::move(c->parameters);
+                        }
 			for (auto &conn : c->connections()) {
 				RTLIL::SigSpec newsig;
 				for (auto c : conn.second.chunks()) {
@@ -621,6 +619,9 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 			}
 		}
 
+                for (auto cell : boxes)
+                        module->remove(cell);
+
 		// Copy connections (and rename) from mapped_mod to module
 		for (auto conn : mapped_mod->connections()) {
 			if (!conn.first.is_fully_const()) {