diff --git a/src/xrGame/ui/UITalkDialogWnd.cpp b/src/xrGame/ui/UITalkDialogWnd.cpp
index f1062084b8c..e5af285d71e 100644
--- a/src/xrGame/ui/UITalkDialogWnd.cpp
+++ b/src/xrGame/ui/UITalkDialogWnd.cpp
@@ -147,10 +147,11 @@ void CUITalkDialogWnd::InitTalkDialogWnd()
     }
 }
 
-void CUITalkDialogWnd::Show()
+void CUITalkDialogWnd::Show(const bool notify_scripts /*= true*/)
 {
     InventoryUtilities::SendInfoToActor("ui_talk_show");
-    InventoryUtilities::SendInfoToLuaScripts("ui_talk_show");
+    if (notify_scripts)
+        InventoryUtilities::SendInfoToLuaScripts("ui_talk_show");
     inherited::Show(true);
     inherited::Enable(true);
 
@@ -159,12 +160,13 @@ void CUITalkDialogWnd::Show()
     UI().Focus().LockToWindow(UIQuestionsList);
 }
 
-void CUITalkDialogWnd::Hide()
+void CUITalkDialogWnd::Hide(const bool notify_scripts /*= true*/)
 {
     if (UI().Focus().GetLocker() == UIQuestionsList)
         UI().Focus().Unlock();
     InventoryUtilities::SendInfoToActor("ui_talk_hide");
-    InventoryUtilities::SendInfoToLuaScripts("ui_talk_hide");
+    if (notify_scripts)
+        InventoryUtilities::SendInfoToLuaScripts("ui_talk_hide");
     inherited::Show(false);
     inherited::Enable(false);
     g_btnHint->Discard();
diff --git a/src/xrGame/ui/UITalkDialogWnd.h b/src/xrGame/ui/UITalkDialogWnd.h
index ace31438e26..b2d1e91f64a 100644
--- a/src/xrGame/ui/UITalkDialogWnd.h
+++ b/src/xrGame/ui/UITalkDialogWnd.h
@@ -26,8 +26,8 @@ class CUITalkDialogWnd final : public CUIWindow, public CUIWndCallback
 
     virtual void SendMessage(CUIWindow* pWnd, s16 msg, void* pData = NULL);
 
-    virtual void Show();
-    virtual void Hide();
+    virtual void Show(bool notify_scripts = true);
+    virtual void Hide(bool notify_scripts = true);
     CUITalkWnd* m_pParent;
     u32 GetHeaderColor() { return m_iNameTextColor; }
     CGameFont* GetHeaderFont() { return m_pNameTextFont; }
diff --git a/src/xrGame/ui/UITalkWnd.cpp b/src/xrGame/ui/UITalkWnd.cpp
index 6e20f333454..55b96a705a7 100644
--- a/src/xrGame/ui/UITalkWnd.cpp
+++ b/src/xrGame/ui/UITalkWnd.cpp
@@ -339,7 +339,9 @@ void CUITalkWnd::SwitchToUpgrade()
         CUIGameSP* pGameSP = smart_cast<CUIGameSP*>(CurrentGameUI());
         if (pGameSP)
         {
-            UITalkDialogWnd->Hide();
+            // Don't notify scripts that we are hiding the dialog because the CoC inventory_upgrade script will mess up otherwise.
+            // See: https://github.com/OpenXRay/xray-16/issues/1852
+            UITalkDialogWnd->Hide(false);
             StopSnd();
 
             pGameSP->StartUpgrade(m_pOurInvOwner, m_pOthersInvOwner);