diff --git a/passes/silimate/annotate_ff_width.cc b/passes/silimate/annotate_ff_width.cc
index 1782fa5ad..5e9488ded 100644
--- a/passes/silimate/annotate_ff_width.cc
+++ b/passes/silimate/annotate_ff_width.cc
@@ -21,6 +21,19 @@
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
+static std::string ff_base_name(const std::string &name)
+{
+	if (!name.empty() && name.back() == ']') {
+		size_t open = name.rfind('[');
+		if (open != std::string::npos && open + 1 < name.size() - 1) {
+			std::string inner = name.substr(open + 1, name.size() - open - 2);
+			if (inner.find_first_not_of("0123456789") == std::string::npos)
+				return name.substr(0, open);
+		}
+	}
+	return name;
+}
+
 struct AnnotateFfWidthPass : public Pass {
 	AnnotateFfWidthPass() : Pass("annotate_ff_width", "annotate every flip-flop with its bit-width") { }
 	void help() override
@@ -43,17 +56,20 @@ struct AnnotateFfWidthPass : public Pass {
 		// Loop through all flip-flops and annotate with their width
 		int annotated = 0;
 		for (auto module : design->selected_modules()) {
+			// Pass 1: count flip-flop cells per base name.
+			dict<std::string, int> name_counts;
+			std::vector<std::pair<RTLIL::Cell *, std::string>> ff_cells;
 			for (auto cell : module->selected_cells()) {
 				if (!RTLIL::builtin_ff_cell_types().count(cell->type))
 					continue;
-				int width;
-				if (cell->hasParam(ID::WIDTH))
-					width = cell->getParam(ID::WIDTH).as_int();
-				else if (cell->hasPort(ID::Q))
-					width = GetSize(cell->getPort(ID::Q));
-				else
-					width = 1;
-				cell->set_string_attribute(ID(ff_width), std::to_string(width));
+				std::string base = ff_base_name(cell->name.str());
+				name_counts[base]++;
+				ff_cells.push_back({cell, base});
+			}
+			// Pass 2: annotate each flip-flop with the count for its base name.
+			for (auto &it : ff_cells) {
+				int width = name_counts[it.second];
+				it.first->set_string_attribute(ID(ff_width), std::to_string(width));
 				annotated++;
 			}
 		}