diff --git a/Source/ImGui/Private/ImGuiImplementation.cpp b/Source/ImGui/Private/ImGuiImplementation.cpp
index 6261002..ac2d97b 100644
--- a/Source/ImGui/Private/ImGuiImplementation.cpp
+++ b/Source/ImGui/Private/ImGuiImplementation.cpp
@@ -6,7 +6,10 @@
 
 // For convenience and easy access to the ImGui source code, we build it as part of this module.
 // We don't need to define IMGUI_API manually because it is already done for this module.
-
+// UE 5.1 stopped defining PLATFORM_XBOXONE, so be safe if not defined
+#if !defined(PLATFORM_XBOXONE)
+	#define PLATFORM_XBOXONE 0
+#endif
 #if PLATFORM_XBOXONE
 // Disable Win32 functions used in ImGui and not supported on XBox.
 #define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS