diff --git a/backends/json/json.cc b/backends/json/json.cc
index 5022d5da1..1781a28cd 100644
--- a/backends/json/json.cc
+++ b/backends/json/json.cc
@@ -189,6 +189,10 @@ struct JsonWriter
 			f << stringf("        %s: {\n", get_name(w->name).c_str());
 			f << stringf("          \"hide_name\": %s,\n", w->name[0] == '$' ? "1" : "0");
 			f << stringf("          \"bits\": %s,\n", get_bits(w).c_str());
+			if (w->start_offset)
+				f << stringf("          \"offset\": %d,\n", w->start_offset);
+			if (w->upto)
+				f << stringf("          \"upto\": 1,\n");
 			f << stringf("          \"attributes\": {");
 			write_parameters(w->attributes);
 			f << stringf("\n          }\n");
diff --git a/frontends/json/jsonparse.cc b/frontends/json/jsonparse.cc
index 82361ea9b..344b8c2c8 100644
--- a/frontends/json/jsonparse.cc
+++ b/frontends/json/jsonparse.cc
@@ -372,6 +372,18 @@ void json_import(Design *design, string &modname, JsonNode *node)
 			if (wire == nullptr)
 				wire = module->addWire(net_name, GetSize(bits_node->data_array));
 
+			if (net_node->data_dict.count("upto") != 0) {
+				JsonNode *val = net_node->data_dict.at("offset");
+				if (val->type == 'N')
+					wire->upto = val->data_number != 0;
+			}
+
+			if (net_node->data_dict.count("offset") != 0) {
+				JsonNode *val = net_node->data_dict.at("offset");
+				if (val->type == 'N')
+					wire->start_offset = val->data_number;
+			}
+
 			for (int i = 0; i < GetSize(bits_node->data_array); i++)
 			{
 				JsonNode *bitval_node = bits_node->data_array.at(i);