diff --git a/src/solanaceae/object_store/fwd.hpp b/src/solanaceae/object_store/fwd.hpp
new file mode 100644
index 0000000..90ec072
--- /dev/null
+++ b/src/solanaceae/object_store/fwd.hpp
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <entt/entity/fwd.hpp>
+
+// internal id
+enum class Object : uint32_t {};
+using ObjectRegistry = entt::basic_registry<Object>;
+using ObjectHandle = entt::basic_handle<ObjectRegistry>;
+
+// fwd
+struct StorageBackendI;
+struct ObjectStore2;
+struct File2I;
+
diff --git a/src/solanaceae/object_store/object_store.hpp b/src/solanaceae/object_store/object_store.hpp
index d468de7..7551c0a 100644
--- a/src/solanaceae/object_store/object_store.hpp
+++ b/src/solanaceae/object_store/object_store.hpp
@@ -3,20 +3,11 @@
 #include <solanaceae/util/event_provider.hpp>
 #include <solanaceae/util/span.hpp>
 
+#include "./fwd.hpp"
+
 #include <entt/entity/registry.hpp>
 #include <entt/entity/handle.hpp>
 
-#include <cstdint>
-
-// internal id
-enum class Object : uint32_t {};
-using ObjectRegistry = entt::basic_registry<Object>;
-using ObjectHandle = entt::basic_handle<ObjectRegistry>;
-
-// fwd
-struct ObjectStore2;
-struct File2I;
-
 struct StorageBackendI {
 	// OR or OS ?
 	ObjectStore2& _os;