diff --git a/libraries/chain/controller.cpp b/libraries/chain/controller.cpp
index c04013cb04..f9c59f26b6 100644
--- a/libraries/chain/controller.cpp
+++ b/libraries/chain/controller.cpp
@@ -3716,22 +3716,6 @@ void controller::code_block_num_last_used(const digest_type& code_hash, uint8_t
    return my->code_block_num_last_used(code_hash, vm_type, vm_version, block_num);
 }
 
-// Native action hardcodes sender empty and builds sender_id from trx id.
-// This method modifies those two fields for contract generated deferred
-// trxs so canceldelay can be tested by canceldelay_test in delay_tests.cpp.
-// It cannot be used for any other purpose.
-void controller::modify_gto_for_canceldelay_test(const transaction_id_type& trx_id) {
-   auto gto = my->db.find<generated_transaction_object, by_trx_id>(trx_id);
-   if (gto) {
-      my->db.modify<generated_transaction_object>(*gto, [&]( auto& gtx ) {
-         gtx.sender = account_name();
-
-         fc::uint128 _id(trx_id._hash[3], trx_id._hash[2]);
-         gtx.sender_id = (unsigned __int128)_id;
-      });
-   }
-}
-
 /// Protocol feature activation handlers:
 
 template<>
diff --git a/libraries/chain/include/eosio/chain/controller.hpp b/libraries/chain/include/eosio/chain/controller.hpp
index e90a97a59f..21c1bc9620 100644
--- a/libraries/chain/include/eosio/chain/controller.hpp
+++ b/libraries/chain/include/eosio/chain/controller.hpp
@@ -366,13 +366,10 @@ namespace eosio { namespace chain {
       bool is_write_window() const;
       void code_block_num_last_used(const digest_type& code_hash, uint8_t vm_type, uint8_t vm_version, uint32_t block_num);
 
-      // Warning: this method is only used by canceldelay_test
-      // in delay_tests.cpp. Do not use it for any other purpose.
-      void modify_gto_for_canceldelay_test(const transaction_id_type& trx_id);
-
       private:
          friend class apply_context;
          friend class transaction_context;
+         friend void modify_gto_for_canceldelay_test(controller& control, const transaction_id_type& trx_id); // canceldelay_test in delay_tests.cpp need access to mutable_db
 
          chainbase::database& mutable_db()const;
 
diff --git a/unittests/delay_tests.cpp b/unittests/delay_tests.cpp
index 2c99288361..122ea997bf 100644
--- a/unittests/delay_tests.cpp
+++ b/unittests/delay_tests.cpp
@@ -16,6 +16,22 @@ using mvo = fc::mutable_variant_object;
 
 const std::string eosio_token = name("eosio.token"_n).to_string();
 
+// Native action hardcodes sender empty and builds sender_id from trx id.
+// This method modifies those two fields for contract generated deferred
+// trxs so canceldelay can be tested by canceldelay_test.
+namespace eosio::chain {
+inline void modify_gto_for_canceldelay_test(controller& control, const transaction_id_type& trx_id) {
+   auto gto = control.mutable_db().find<generated_transaction_object, by_trx_id>(trx_id);
+   if (gto) {
+      control.mutable_db().modify<generated_transaction_object>(*gto, [&]( auto& gtx ) {
+         gtx.sender = account_name();
+
+         fc::uint128 _id(trx_id._hash[3], trx_id._hash[2]);
+         gtx.sender_id = (unsigned __int128)_id;
+      });
+   }
+}} /// namespace eosio::chain
+
 static void create_accounts(validating_tester& chain) {
    chain.produce_blocks();
    chain.create_accounts({"eosio.msig"_n, "eosio.token"_n});
@@ -1392,7 +1408,7 @@ BOOST_AUTO_TEST_CASE( canceldelay_test ) { try {
 
    // canceldelay assumes sender and sender_id to be a specific
    // format. hardcode them for testing purpose only
-   chain.control->modify_gto_for_canceldelay_test(deferred_id);
+   modify_gto_for_canceldelay_test(*(chain.control.get()), deferred_id);
 
    // send canceldelay for the delayed transaction
    signed_transaction trx;
@@ -1451,7 +1467,7 @@ BOOST_AUTO_TEST_CASE( canceldelay_test2 ) { try {
 
    // canceldelay assumes sender and sender_id to be a specific
    // format. hardcode them for testing purpose only
-   chain.control->modify_gto_for_canceldelay_test(deferred_id);
+   modify_gto_for_canceldelay_test(*(chain.control.get()), deferred_id);
 
    // attempt canceldelay with wrong canceling_auth for delayed trx
    {