diff --git a/src/errors.h b/src/errors.h
index 7f23cc8..868ed57 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3332,4 +3332,6 @@
 #ifdef FEAT_EVAL
 EXTERN char e_loop_nesting_too_deep[]
 	INIT(= N_("E1306: Loop nesting too deep"));
+EXTERN char e_argument_nr_trying_to_modify_const_str[]
+	INIT(= N_("E1307: Argument %d: Trying to modify a const %s"));
 #endif