diff --git a/src/proto/optionstr.pro b/src/proto/optionstr.pro
index c034c11..561faa8 100644
--- a/src/proto/optionstr.pro
+++ b/src/proto/optionstr.pro
@@ -99,6 +99,7 @@
 int expand_set_highlight(optexpand_T *args, int *numMatches, char_u ***matches);
 char *did_set_iconstring(optset_T *args);
 char *did_set_imactivatekey(optset_T *args);
+char *did_set_iskeyword(optset_T *args);
 char *did_set_isopt(optset_T *args);
 char *did_set_jumpoptions(optset_T *args);
 int expand_set_jumpoptions(optexpand_T *args, int *numMatches, char_u ***matches);