Cast argument to set_panel_userptr to void*. Fixes bug #417240.
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
index 42abc2a..feecfcc 100644
--- a/Modules/_curses_panel.c
+++ b/Modules/_curses_panel.c
@@ -304,7 +304,7 @@
     }
     obj = PyTuple_GetItem(args, 0);
     Py_INCREF(obj);
-    return PyCursesCheckERR(set_panel_userptr(self->pan, obj),
+    return PyCursesCheckERR(set_panel_userptr(self->pan, (void*)obj),
                             "set_panel_userptr");
 }