diff --git a/ext/dom/php_dom.c b/ext/dom/php_dom.c
index 216cb81a083..c070b98cfb1 100644
--- a/ext/dom/php_dom.c
+++ b/ext/dom/php_dom.c
@@ -1869,7 +1869,7 @@ static bool dom_match_qualified_name_for_tag_name_equality(const xmlChar *local,
 	return dom_match_qualified_name_according_to_spec(local_to_use, nodep);
 }
 
-xmlNode *dom_get_elements_by_tag_name_ns_raw(xmlNodePtr basep, xmlNodePtr nodep, xmlChar *ns, xmlChar *local, zend_string *local_lower, zend_long *cur, zend_long index) /* {{{ */
+xmlNode *dom_get_elements_by_tag_name_ns_raw(xmlNodePtr basep, xmlNodePtr nodep, const xmlChar *ns, const xmlChar *local, const zend_string *local_lower, zend_long *cur, zend_long index) /* {{{ */
 {
 	/* Can happen with detached document */
 	if (UNEXPECTED(nodep == NULL)) {
diff --git a/ext/dom/php_dom.h b/ext/dom/php_dom.h
index 060861ee996..8a1dc567a3c 100644
--- a/ext/dom/php_dom.h
+++ b/ext/dom/php_dom.h
@@ -145,7 +145,7 @@ void dom_reconcile_ns_list(xmlDocPtr doc, xmlNodePtr nodep, xmlNodePtr last);
 xmlNsPtr dom_get_nsdecl(xmlNode *node, xmlChar *localName);
 void php_dom_normalize_legacy(xmlNodePtr nodep);
 void php_dom_normalize_modern(xmlNodePtr nodep);
-xmlNode *dom_get_elements_by_tag_name_ns_raw(xmlNodePtr basep, xmlNodePtr nodep, xmlChar *ns, xmlChar *local, zend_string *local_lower, zend_long *cur, zend_long index);
+xmlNode *dom_get_elements_by_tag_name_ns_raw(xmlNodePtr basep, xmlNodePtr nodep, const xmlChar *ns, const xmlChar *local, const zend_string *local_lower, zend_long *cur, zend_long index);
 void php_dom_create_implementation(zval *retval, bool modern);
 int dom_hierarchy(xmlNodePtr parent, xmlNodePtr child);
 bool dom_has_feature(zend_string *feature, zend_string *version);