diff --git a/builtin-revert.c b/builtin-revert.c
index 55d4fa1e6..ea2f15b97 100644
--- a/builtin-revert.c
+++ b/builtin-revert.c
@@ -133,7 +133,7 @@ static void add_to_msg(const char *string)
 {
 	int len = strlen(string);
 	if (write_in_full(msg_fd, string, len) < 0)
-		die ("Could not write to .msg");
+		die ("Could not write to MERGE_MSG");
 }
 
 static void add_message_to_msg(const char *message)