diff --git a/Source/Client/Session.cpp b/Source/Client/Session.cpp
index b199197b..37bb3fe5 100644
--- a/Source/Client/Session.cpp
+++ b/Source/Client/Session.cpp
@@ -15,6 +15,7 @@
 #include "Network/TextEncoding.h"
 #include "UI/Window/UIWindowMgr.h"
 #include "UI/Window/UIWindow.h"
+#include "UI/Window/WindowOrdering.h"
 #include "Contents/Configuration/ServiceOptions.h"
 #include "Contents/MessageTable.h"
 #include "Contents/PlayerNameDictionary.h"
@@ -1911,3 +1912,9 @@ int CSession::CountItems17F0() const {
 
   return count;
 }
+
+// OFFSET: 0x00DF9500
+// FUNCTION: fn_23518
+void CSession::InvalidateWindowFrames() {
+  reinterpret_cast<WindowOrdering&>(g_windowMgr).InvalidateFrames(g_windowMgr.unknown_04FC);
+}
diff --git a/Source/Client/Session.h b/Source/Client/Session.h
index 4142e295..1c812e7b 100644
--- a/Source/Client/Session.h
+++ b/Source/Client/Session.h
@@ -802,6 +802,7 @@ public:
   void RefreshHomunculusInfo();
   void RefreshMercenaryInfo();
   bool IsBlankString(const char* text) const;
+  void InvalidateWindowFrames();
   void EraseRecord0734(int id);
   void IgnoreText(std::string text);
   void SaveMiniPartyInfo();