diff --git a/src/proto/vim9expr.pro b/src/proto/vim9expr.pro
new file mode 100644
index 0000000..aa84509
--- /dev/null
+++ b/src/proto/vim9expr.pro
@@ -0,0 +1,17 @@
+/* vim9expr.c */
+int generate_ppconst(cctx_T *cctx, ppconst_T *ppconst);
+void clear_ppconst(ppconst_T *ppconst);
+int compile_member(int is_slice, int *keeping_dict, cctx_T *cctx);
+int compile_load_scriptvar(cctx_T *cctx, char_u *name, char_u *start, char_u **end, int error);
+int compile_load(char_u **arg, char_u *end_arg, cctx_T *cctx, int is_expr, int error);
+char_u *to_name_end(char_u *arg, int use_namespace);
+char_u *to_name_const_end(char_u *arg);
+int get_lambda_tv_and_compile(char_u **arg, typval_T *rettv, int types_optional, evalarg_T *evalarg);
+exprtype_T get_compare_type(char_u *p, int *len, int *type_is);
+void skip_expr_cctx(char_u **arg, cctx_T *cctx);
+int bool_on_stack(cctx_T *cctx);
+void error_white_both(char_u *op, int len);
+int compile_expr1(char_u **arg, cctx_T *cctx, ppconst_T *ppconst);
+int compile_expr0_ext(char_u **arg, cctx_T *cctx, int *is_const);
+int compile_expr0(char_u **arg, cctx_T *cctx);
+/* vim: set ft=c : */