diff --git a/c_gen/c_code_gen.py b/c_gen/c_code_gen.py
index cbbcfba..e987874 100644
--- a/c_gen/c_code_gen.py
+++ b/c_gen/c_code_gen.py
@@ -437,6 +437,7 @@
 of_object_id_t of_action_to_object_id(int action, of_version_t version);
 of_object_id_t of_action_id_to_object_id(int action_id, of_version_t version);
 of_object_id_t of_instruction_to_object_id(int instruction, of_version_t version);
+of_object_id_t of_instruction_id_to_object_id(int instruction, of_version_t version);
 of_object_id_t of_queue_prop_to_object_id(int queue_prop, of_version_t version);
 of_object_id_t of_table_feature_prop_to_object_id(int table_feature_prop, of_version_t version);
 of_object_id_t of_meter_band_to_object_id(int meter_band, of_version_t version);