diff --git a/src/proto/message.pro b/src/proto/message.pro
index c9d62c6..9a79f14 100644
--- a/src/proto/message.pro
+++ b/src/proto/message.pro
@@ -8,6 +8,7 @@
 void reset_last_sourcing(void);
 void msg_source(int attr);
 int emsg_not_now(void);
+void ignore_error_for_testing(char_u *error);
 void do_perror(char *msg);
 int emsg(char_u *s);
 int emsg2(char_u *s, char_u *a1);