diff --git a/src/errors.h b/src/errors.h
index 6d3d06d26b..da45df2100 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -2944,7 +2944,7 @@ EXTERN char e_cannot_change_arglist_recursively[]
 EXTERN char e_missing_return_type[]
 	INIT(= N_("E1157: Missing return type"));
 EXTERN char e_cannot_use_flatten_in_vim9_script[]
-	INIT(= N_("E1158: Cannot use flatten() in Vim9 script"));
+	INIT(= N_("E1158: Cannot use flatten() in Vim9 script, use flattennew()"));
 #endif
 EXTERN char e_cannot_split_window_when_closing_buffer[]
 	INIT(= N_("E1159: Cannot split a window when closing the buffer"));
diff --git a/src/version.c b/src/version.c
index 3d37eec6a2..fff4e6dd3f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4240,
 /**/
     4239,
 /**/