diff --git a/src/proto.h b/src/proto.h
index 729fea3..b5a6224 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -127,7 +127,8 @@
 #  endif
 vim_snprintf(char *, size_t, char *, ...);
 
-int vim_vsnprintf(char *str, size_t str_m, char *fmt, va_list ap, typval_T *tvs);
+int vim_vsnprintf(char *str, size_t str_m, char *fmt, va_list ap);
+int vim_vsnprintf_typval(char *str, size_t str_m, char *fmt, va_list ap, typval_T *tvs);
 
 # include "message.pro"
 # include "misc1.pro"