diff --git a/src/vim.h b/src/vim.h
index 4c9e095..844627d 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1201,6 +1201,7 @@
 #define OPT_NOWIN	0x20	// don't set window-local options
 #define OPT_ONECOLUMN	0x40	// list options one per line
 #define OPT_NO_REDRAW	0x80	// ignore redraw flags on option
+#define OPT_SKIPRTP	0x100	// "skiprtp" in 'sessionoptions'
 
 // Magic chars used in confirm dialog strings
 #define DLG_BUTTON_SEP	'\n'