diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 362b9d9..d520046 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -61,6 +61,7 @@
 long get_vim_var_nr __ARGS((int idx));
 char_u *get_vim_var_str __ARGS((int idx));
 list_T *get_vim_var_list __ARGS((int idx));
+void set_vim_var_char __ARGS((int c));
 void set_vcount __ARGS((long count, long count1, int set_prevcount));
 void set_vim_var_string __ARGS((int idx, char_u *val, int len));
 void set_vim_var_list __ARGS((int idx, list_T *val));