diff --git a/binding-sandbox/sandbox-serial-util.h b/binding-sandbox/sandbox-serial-util.h
index d7ceffc3..fe018807 100644
--- a/binding-sandbox/sandbox-serial-util.h
+++ b/binding-sandbox/sandbox-serial-util.h
@@ -79,14 +79,14 @@ namespace mkxp_sandbox {
             using namespace mkxp_sandbox;
 
             if (ptr == nullptr) {
-                if (!mkxp_sandbox::sandbox_serialize((uint32_t)2, data, max_size)) return false;
+                if (!mkxp_sandbox::sandbox_serialize((uint8_t)2, data, max_size)) return false;
             } else {
                 const auto &it = map.find(ptr);
                 if (it != map.end()) {
-                    if (!mkxp_sandbox::sandbox_serialize((uint32_t)(it->second.is_extra ? 1 : 0), data, max_size)) return false;
+                    if (!mkxp_sandbox::sandbox_serialize((uint8_t)(it->second.is_extra ? 1 : 0), data, max_size)) return false;
                     if (!mkxp_sandbox::sandbox_serialize(it->second.key, data, max_size)) return false;
                 } else {
-                    if (!mkxp_sandbox::sandbox_serialize((uint32_t)1, data, max_size)) return false;
+                    if (!mkxp_sandbox::sandbox_serialize((uint8_t)1, data, max_size)) return false;
 
                     constexpr wasm_size_t typenum = get_typenum<T>::value;
                     extra_objects.emplace_back((const void *)ptr, typenum);
diff --git a/src/display/bitmap.cpp b/src/display/bitmap.cpp
index 7e6e10c0..c5d27a37 100644
--- a/src/display/bitmap.cpp
+++ b/src/display/bitmap.cpp
@@ -3392,6 +3392,9 @@ void Bitmap::loresDisposal()
 #ifdef MKXPZ_RETRO
 bool Bitmap::_sandbox_serialize_inner(void *&data, mkxp_sandbox::wasm_size_t &max_size) const
 {
+    if (isDisposed()) return mkxp_sandbox::sandbox_serialize(false, data, max_size);
+    if (!mkxp_sandbox::sandbox_serialize(true, data, max_size)) return false;
+
     if (!mkxp_sandbox::sandbox_serialize((int32_t)width(), data, max_size)) return false;
     if (!mkxp_sandbox::sandbox_serialize((int32_t)height(), data, max_size)) return false;
     if (!mkxp_sandbox::sandbox_serialize(p->animation.enabled, data, max_size)) return false;
@@ -3416,9 +3419,6 @@ bool Bitmap::_sandbox_serialize_inner(void *&data, mkxp_sandbox::wasm_size_t &ma
 
 bool Bitmap::sandbox_serialize(void *&data, mkxp_sandbox::wasm_size_t &max_size) const
 {
-    if (isDisposed()) return mkxp_sandbox::sandbox_serialize(false, data, max_size);
-    if (!mkxp_sandbox::sandbox_serialize(true, data, max_size)) return false;
-
     if (!mkxp_sandbox::sandbox_serialize(p->selfHires != nullptr, data, max_size)) return false;
 
     if (p->selfHires != nullptr) {