diff --git a/src/vim.h b/src/vim.h
index 97c1f6c..fe1e982 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -632,6 +632,7 @@
 #define POPF_MAPPING	0x80	// mapping keys
 #define POPF_INFO	0x100	// used for info of popup menu
 #define POPF_INFO_MENU	0x200	// align info popup with popup menu
+#define POPF_POSINVERT	0x400	// vertical position can be inverted
 
 #ifdef FEAT_TEXT_PROP
 # define WIN_IS_POPUP(wp) ((wp)->w_popup_flags != 0)