diff --git a/MUNGA_L4/L4VB16.cpp b/MUNGA_L4/L4VB16.cpp
index fad4f98..f0e60a5 100644
--- a/MUNGA_L4/L4VB16.cpp
+++ b/MUNGA_L4/L4VB16.cpp
@@ -3828,6 +3828,13 @@ static LRESULT CALLBACK
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 static WNDPROC gCockpitBaseProc = NULL;
 
+//
+// Which window we subclassed, so the destructor can put its own proc
+// back. The shell is the GAME window: it outlives the cockpit and
+// carries the console screen from one race to the next.
+//
+static HWND gCockpitShellWindow = NULL;
+
 static LRESULT CALLBACK
 	CockpitShellProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
@@ -4688,9 +4695,25 @@ SVGA16::SVGA16(
 			GetClientRect(cockpit, &inner);
 			LayoutCockpit(inner.right, inner.bottom);
 
-			// catch maximise / restore / drag-resize and re-fit
-			gCockpitBaseProc = (WNDPROC) SetWindowLongPtrA(
-				cockpit, GWLP_WNDPROC, (LONG_PTR) CockpitShellProc);
+			//
+			// Catch maximise / restore / drag-resize and re-fit - ONCE.
+			//
+			// The destructor puts the original proc back, so ordinarily
+			// this window is unsubclassed by the time a second race
+			// builds a new cockpit. The guard is for the case where it
+			// was not: subclassing an already-subclassed window makes
+			// SetWindowLongPtr hand back CockpitShellProc itself as the
+			// "original", and the proc below then chains to itself on
+			// every single message until the stack runs out. That is a
+			// stack overflow a few frames into the second race, with no
+			// hint of a cause in the log.
+			//
+			if (gCockpitShellWindow != cockpit)
+			{
+				gCockpitBaseProc = (WNDPROC) SetWindowLongPtrA(
+					cockpit, GWLP_WNDPROC, (LONG_PTR) CockpitShellProc);
+				gCockpitShellWindow = cockpit;
+			}
 
 			//
 			// Sticky placement for the shell. Position AND size: nothing
@@ -4926,6 +4949,30 @@ SVGA16::~SVGA16()
 		cockpitViewscreen = NULL;
 	}
 
+	//
+	// Give the game window its own proc back, and stop answering for a
+	// cockpit that is about to stop existing.
+	//
+	// The window survives us - it is the one that shows the console
+	// screen between races - so both of these outlived their subject.
+	// The subclass was the worse of the two: the next race re-subclassed
+	// the same window and CockpitShellProc ended up chained to itself.
+	// activeCockpit was the quieter one, left pointing at this object
+	// after it was freed, ready for the next WM_SIZE to lay out a
+	// cockpit that had already gone.
+	//
+	if (gCockpitShellWindow != NULL)
+	{
+		SetWindowLongPtrA(
+			gCockpitShellWindow, GWLP_WNDPROC, (LONG_PTR) gCockpitBaseProc);
+		gCockpitShellWindow = NULL;
+		gCockpitBaseProc = NULL;
+	}
+	if (activeCockpit == this)
+	{
+		activeCockpit = NULL;
+	}
+
 	Check_Fpu();
 }