diff --git a/src/KingSystem/GameData/CMakeLists.txt b/src/KingSystem/GameData/CMakeLists.txt
index 110642fa..47aa4b50 100644
--- a/src/KingSystem/GameData/CMakeLists.txt
+++ b/src/KingSystem/GameData/CMakeLists.txt
@@ -5,6 +5,7 @@ target_sources(uking PRIVATE
   gdtCommonFlagsUtils.h
   gdtFlag.cpp
   gdtFlag.h
+  gdtFlagHandle.h
   gdtFlagProxy.h
   gdtFlagUtils.h
   gdtManager.cpp
diff --git a/src/KingSystem/GameData/gdtFlagHandle.h b/src/KingSystem/GameData/gdtFlagHandle.h
new file mode 100644
index 00000000..cac206c3
--- /dev/null
+++ b/src/KingSystem/GameData/gdtFlagHandle.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <basis/seadTypes.h>
+
+namespace ksys::gdt {
+
+enum class FlagHandle : u32 {};
+
+constexpr FlagHandle InvalidHandle = FlagHandle(-1);
+
+}  // namespace ksys::gdt
diff --git a/src/KingSystem/GameData/gdtManager.h b/src/KingSystem/GameData/gdtManager.h
index c480977e..2ddc0308 100644
--- a/src/KingSystem/GameData/gdtManager.h
+++ b/src/KingSystem/GameData/gdtManager.h
@@ -9,6 +9,7 @@
 #include <prim/seadTypedBitFlag.h>
 #include <thread/seadMutex.h>
 #include <type_traits>
+#include "KingSystem/GameData/gdtFlagHandle.h"
 #include "KingSystem/GameData/gdtTriggerParam.h"
 #include "KingSystem/Resource/resHandle.h"
 #include "KingSystem/System/KingEditor.h"
@@ -56,10 +57,6 @@ struct SetterTraits {
 
 }  // namespace detail
 
-enum class FlagHandle : u32 {};
-
-constexpr FlagHandle InvalidHandle = FlagHandle(-1);
-
 class TriggerParamRef {
 public:
     TriggerParamRef(TriggerParam** param_1, TriggerParam** param, bool check_permissions,