diff --git a/src/proto/evalfunc.pro b/src/proto/evalfunc.pro
index da1c324..78998ff 100644
--- a/src/proto/evalfunc.pro
+++ b/src/proto/evalfunc.pro
@@ -7,7 +7,7 @@
 char *internal_func_name(int idx);
 int internal_func_check_arg_types(type2_T *types, int idx, int argcount, cctx_T *cctx);
 void internal_func_get_argcount(int idx, int *argcount, int *min_argcount);
-type_T *internal_func_ret_type(int idx, int argcount, type2_T *argtypes, type_T **decl_type);
+type_T *internal_func_ret_type(int idx, int argcount, type2_T *argtypes, type_T **decl_type, garray_T *type_gap);
 int internal_func_is_map(int idx);
 int check_internal_func(int idx, int argcount);
 int call_internal_func(char_u *name, int argcount, typval_T *argvars, typval_T *rettv);