diff --git a/src/option.c b/src/option.c
index 98ef98a..f47549d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -1049,7 +1049,7 @@
 								     |P_NODUP,
 #ifdef FEAT_DIFF
 			    (char_u *)&p_dip, PV_NONE,
-			    {(char_u *)"filler", (char_u *)NULL}
+			    {(char_u *)"internal,filler", (char_u *)NULL}
 #else
 			    (char_u *)NULL, PV_NONE,
 			    {(char_u *)"", (char_u *)NULL}