api CHANGE use const where should be
diff --git a/src/printer.h b/src/printer.h
index 36a8307..eb13049 100644
--- a/src/printer.h
+++ b/src/printer.h
@@ -56,14 +56,14 @@
int ly_print(struct lyout *out, const char *format, ...);
int ly_write(struct lyout *out, const char *buf, size_t count);
-int yang_print_model(struct lyout *out, struct lys_module *module);
-int tree_print_model(struct lyout *out, struct lys_module *module);
-int info_print_model(struct lyout *out, struct lys_module *module, const char *target_node);
+int yang_print_model(struct lyout *out, const struct lys_module *module);
+int tree_print_model(struct lyout *out, const struct lys_module *module);
+int info_print_model(struct lyout *out, const struct lys_module *module, const char *target_node);
-int json_print_data(struct lyout *out, struct lyd_node *root);
-int xml_print_data(struct lyout *out, struct lyd_node *root, int format);
+int json_print_data(struct lyout *out, const struct lyd_node *root);
+int xml_print_data(struct lyout *out, const struct lyd_node *root, int format);
/* 0 - same, 1 - different */
-int nscmp(struct lyd_node *node1, struct lyd_node *node2);
+int nscmp(const struct lyd_node *node1, const struct lyd_node *node2);
#endif /* LY_PRINTER_H_ */