diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 6f16ce0..3bbe815 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -121,15 +121,15 @@
 void reset_v_option_vars(void);
 void prepare_assert_error(garray_T *gap);
 void assert_error(garray_T *gap);
-void assert_equal_common(typval_T *argvars, assert_type_T atype);
-void assert_equalfile(typval_T *argvars);
-void assert_match_common(typval_T *argvars, assert_type_T atype);
-void assert_inrange(typval_T *argvars);
-void assert_bool(typval_T *argvars, int isTrue);
-void assert_report(typval_T *argvars);
-void assert_exception(typval_T *argvars);
-void assert_beeps(typval_T *argvars);
-void assert_fails(typval_T *argvars);
+int assert_equal_common(typval_T *argvars, assert_type_T atype);
+int assert_equalfile(typval_T *argvars);
+int assert_match_common(typval_T *argvars, assert_type_T atype);
+int assert_inrange(typval_T *argvars);
+int assert_bool(typval_T *argvars, int isTrue);
+int assert_report(typval_T *argvars);
+int assert_exception(typval_T *argvars);
+int assert_beeps(typval_T *argvars);
+int assert_fails(typval_T *argvars);
 void fill_assert_error(garray_T *gap, typval_T *opt_msg_tv, char_u *exp_str, typval_T *exp_tv, typval_T *got_tv, assert_type_T atype);
 int typval_compare(typval_T *typ1, typval_T *typ2, exptype_T type, int type_is, int ic);
 char_u *typval_tostring(typval_T *arg);