diff --git a/binding-sandbox/sandbox-serial-util.h b/binding-sandbox/sandbox-serial-util.h
index 54eeb414..68342cdd 100644
--- a/binding-sandbox/sandbox-serial-util.h
+++ b/binding-sandbox/sandbox-serial-util.h
@@ -71,7 +71,7 @@ namespace mkxp_sandbox {
             for (const auto &object : sb()->get_objects()) {
                 ++key;
                 if (object.typenum == get_typenum<T>::value) {
-                    map.insert({(T *)object.inner.ptr, (struct info){.key = key, .is_extra = false}});
+                    map.emplace((T *)object.inner.ptr, (struct info){.key = key, .is_extra = false});
                 }
             }
         }
@@ -91,7 +91,7 @@ namespace mkxp_sandbox {
 
                     constexpr wasm_size_t typenum = get_typenum<T>::value;
                     extra_objects.emplace_back((const void *)ptr, typenum);
-                    map.insert({ptr, (struct info){.key = (wasm_objkey_t)extra_objects.size(), .is_extra = true}});
+                    map.emplace(ptr, (struct info){.key = (wasm_objkey_t)extra_objects.size(), .is_extra = true});
 
                     if (!mkxp_sandbox::sandbox_serialize((wasm_objkey_t)extra_objects.size(), data, max_size)) return false;
                 }
diff --git a/src/core.cpp b/src/core.cpp
index 501cfaf5..de8189a8 100644
--- a/src/core.cpp
+++ b/src/core.cpp
@@ -1684,11 +1684,6 @@ extern "C" RETRO_API bool retro_serialize(void *data, size_t len) {
             if (!typenum_table[typenum - 1].serialize(ptr, data, max_size)) OBJECTS_END_FAIL;
         }
     }
-    if (num_free_objects > 0) {
-        if (!sandbox_serialize((wasm_size_t)0, data, max_size)) OBJECTS_END_FAIL;
-        if (!sandbox_serialize(num_free_objects, data, max_size)) OBJECTS_END_FAIL;
-        num_free_objects = 0;
-    }
     *num_extra_objects_ptr = (wasm_size_t)extra_objects.size();
 
     OBJECTS_END;