diff --git a/src/winconpty/winconpty.h b/src/winconpty/winconpty.h
index 44d1fdbfd7e..289c42e5f28 100644
--- a/src/winconpty/winconpty.h
+++ b/src/winconpty/winconpty.h
@@ -39,6 +39,7 @@ HRESULT _CreatePseudoConsole(const HANDLE hToken,
 
 HRESULT _ResizePseudoConsole(_In_ const PseudoConsole* const pPty, _In_ const COORD size);
 HRESULT _ClearPseudoConsole(_In_ const PseudoConsole* const pPty);
+HRESULT _ShowHidePseudoConsole(_In_ const PseudoConsole* const pPty, const bool show);
 HRESULT _ReparentPseudoConsole(_In_ const PseudoConsole* const pPty, _In_ const HWND newParent);
 void _ClosePseudoConsoleMembers(_In_ PseudoConsole* pPty);
 VOID _ClosePseudoConsole(_In_ PseudoConsole* pPty);