diff --git a/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/config.hpp b/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/config.hpp
index 43f9efede2..c7278931e4 100644
--- a/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/config.hpp
+++ b/libraries/chain/include/eosio/chain/webassembly/eos-vm-oc/config.hpp
@@ -5,7 +5,7 @@
 #include <vector>
 #include <string>
 
-#include <fc/reflect/reflect.hpp>
+#include <fc/io/raw.hpp>
 
 #include <sys/resource.h>
 
@@ -25,6 +25,34 @@ struct config {
    std::optional<size_t>   generated_code_size_limit {16u*1024u*1024u};
 };
 
-}}}
+//work around unexpected std::optional behavior
+template <typename DS>
+inline DS& operator>>(DS& ds, eosio::chain::eosvmoc::config& cfg) {
+   fc::raw::pack(ds, cfg.cache_size);
+   fc::raw::pack(ds, cfg.threads);
+
+   auto better_optional_unpack = [&]<typename T>(std::optional<T>& t) {
+      bool b; fc::raw::unpack( ds, b );
+      if(b) { t = T(); fc::raw::unpack( ds, *t ); }
+      else { t.reset(); }
+   };
+   better_optional_unpack(cfg.cpu_limit);
+   better_optional_unpack(cfg.vm_limit);
+   better_optional_unpack(cfg.stack_size_limit);
+   better_optional_unpack(cfg.generated_code_size_limit);
+
+   return ds;
+}
+
+template <typename DS>
+inline DS& operator<<(DS& ds, const eosio::chain::eosvmoc::config& cfg) {
+   fc::raw::pack(ds, cfg.cache_size);
+   fc::raw::pack(ds, cfg.threads);
+   fc::raw::pack(ds, cfg.cpu_limit);
+   fc::raw::pack(ds, cfg.vm_limit);
+   fc::raw::pack(ds, cfg.stack_size_limit);
+   fc::raw::pack(ds, cfg.generated_code_size_limit);
+   return ds;
+}
 
-FC_REFLECT(eosio::chain::eosvmoc::config, (cache_size)(threads)(cpu_limit)(vm_limit)(stack_size_limit)(generated_code_size_limit))
+}}}
diff --git a/unittests/eosvmoc_limits_tests.cpp b/unittests/eosvmoc_limits_tests.cpp
index 4bf3e0cff2..72ec3c0700 100644
--- a/unittests/eosvmoc_limits_tests.cpp
+++ b/unittests/eosvmoc_limits_tests.cpp
@@ -71,6 +71,15 @@ void limit_not_violated_test(const eosvmoc::config& eosvmoc_config) {
    );
 }
 
+static eosvmoc::config make_eosvmoc_config_without_limits() {
+   eosvmoc::config cfg;
+   cfg.cpu_limit.reset();
+   cfg.vm_limit.reset();
+   cfg.stack_size_limit.reset();
+   cfg.generated_code_size_limit.reset();
+   return cfg;
+}
+
 // test all limits are not set for tests
 BOOST_AUTO_TEST_CASE( limits_not_set ) { try {
    validating_tester chain;
@@ -85,13 +94,13 @@ BOOST_AUTO_TEST_CASE( limits_not_set ) { try {
 // test limits are not enforced unless limits in eosvmoc_config
 // are modified
 BOOST_AUTO_TEST_CASE( limits_not_enforced ) { try {
-   eosvmoc::config eosvmoc_config;
+   eosvmoc::config eosvmoc_config = make_eosvmoc_config_without_limits();
    limit_not_violated_test(eosvmoc_config);
 } FC_LOG_AND_RETHROW() }
 
 // test VM limit are checked
 BOOST_AUTO_TEST_CASE( vm_limit ) { try {
-   eosvmoc::config eosvmoc_config;
+   eosvmoc::config eosvmoc_config = make_eosvmoc_config_without_limits();
 
    // set vm_limit to a small value such that it is exceeded
    eosvmoc_config.vm_limit = 64u*1024u*1024u;
@@ -104,7 +113,7 @@ BOOST_AUTO_TEST_CASE( vm_limit ) { try {
 
 // test stack size limit is checked
 BOOST_AUTO_TEST_CASE( stack_limit ) { try {
-   eosvmoc::config eosvmoc_config;
+   eosvmoc::config eosvmoc_config = make_eosvmoc_config_without_limits();
 
    // The stack size of the compiled WASM in the test is 104.
    // Set stack_size_limit one less than the actual needed stack size
@@ -118,7 +127,7 @@ BOOST_AUTO_TEST_CASE( stack_limit ) { try {
 
 // test generated code size limit is checked
 BOOST_AUTO_TEST_CASE( generated_code_size_limit ) { try {
-   eosvmoc::config eosvmoc_config;
+   eosvmoc::config eosvmoc_config = make_eosvmoc_config_without_limits();
 
    // The generated code size of the compiled WASM in the test is 36856.
    // Set generated_code_size_limit to the actual generated code size