diff --git a/src/errors.h b/src/errors.h
index 0e0377a..eec45df 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -288,4 +288,8 @@
 	INIT(= N_("E1131: Cannot add to null blob"));
 EXTERN char e_missing_function_argument[]
 	INIT(= N_("E1132: Missing function argument"));
+EXTERN char e_cannot_extend_null_dict[]
+	INIT(= N_("E1133: Cannot extend a null dict"));
+EXTERN char e_cannot_extend_null_list[]
+	INIT(= N_("E1134: Cannot extend a null list"));
 #endif