diff --git a/ext/dom/node.c b/ext/dom/node.c
index 4a797c573a450..b95bf6c40fb4c 100644
--- a/ext/dom/node.c
+++ b/ext/dom/node.c
@@ -1490,33 +1490,58 @@ static bool php_dom_node_is_equal_node(const xmlNode *this, const xmlNode *other
 
 #define PHP_DOM_FUNC_CAT(prefix, suffix) prefix##_##suffix
 /* xmlNode and xmlNs have incompatible struct layouts, i.e. the next field is in a different offset */
-#define PHP_DOM_DEFINE_LIST_EQUALITY_HELPER(type)																\
-	static size_t PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(const type *node)						\
-	{																											\
-		size_t counter = 0;																						\
-		while (node) {																							\
-			counter++;																							\
-			node = node->next;																					\
-		}																										\
-		return counter;																							\
-	}																											\
-	static bool PHP_DOM_FUNC_CAT(php_dom_node_list_equality_check, type)(const type *list1, const type *list2)	\
-	{																											\
-		size_t count = PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(list1);								\
-		if (count != PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(list2)) {								\
-			return false;																						\
-		}																										\
-		for (size_t i = 0; i < count; i++) {																	\
-			if (!php_dom_node_is_equal_node((const xmlNode *) list1, (const xmlNode *) list2)) {				\
-				return false;																					\
-			}																									\
-			list1 = list1->next;																				\
-			list2 = list2->next;																				\
-		}																										\
-		return true;																							\
-	}
-PHP_DOM_DEFINE_LIST_EQUALITY_HELPER(xmlNode)
-PHP_DOM_DEFINE_LIST_EQUALITY_HELPER(xmlNs)
+#define PHP_DOM_DEFINE_LIST_COUNTER_HELPER(type)																		\
+	static size_t PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(const type *node)								\
+	{																													\
+		size_t counter = 0;																								\
+		while (node) {																									\
+			counter++;																									\
+			node = node->next;																							\
+		}																												\
+		return counter;																									\
+	}
+#define PHP_DOM_DEFINE_LIST_EQUALITY_ORDERED_HELPER(type)																\
+	static bool PHP_DOM_FUNC_CAT(php_dom_node_list_equality_check_ordered, type)(const type *list1, const type *list2)	\
+	{																													\
+		size_t count = PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(list1);										\
+		if (count != PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(list2)) {										\
+			return false;																								\
+		}																												\
+		for (size_t i = 0; i < count; i++) {																			\
+			if (!php_dom_node_is_equal_node((const xmlNode *) list1, (const xmlNode *) list2)) {						\
+				return false;																							\
+			}																											\
+			list1 = list1->next;																						\
+			list2 = list2->next;																						\
+		}																												\
+		return true;																									\
+	}
+#define PHP_DOM_DEFINE_LIST_EQUALITY_UNORDERED_HELPER(type)																\
+	static bool PHP_DOM_FUNC_CAT(php_dom_node_list_equality_check_unordered, type)(const type *list1, const type *list2)\
+	{																													\
+		size_t count = PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(list1);										\
+		if (count != PHP_DOM_FUNC_CAT(php_dom_node_count_list_size, type)(list2)) {										\
+			return false;																								\
+		}																												\
+		for (const type *n1 = list1; n1 != NULL; n1 = n1->next) {														\
+			bool found = false;																							\
+			for (const type *n2 = list2; n2 != NULL && !found; n2 = n2->next) {											\
+				if (php_dom_node_is_equal_node((const xmlNode *) n1, (const xmlNode *) n2)) {							\
+					found = true;																						\
+				}																										\
+			}																											\
+			if (!found) {																								\
+				return false;																							\
+			}																											\
+		}																												\
+		return true;																									\
+	}
+
+PHP_DOM_DEFINE_LIST_COUNTER_HELPER(xmlNode)
+PHP_DOM_DEFINE_LIST_COUNTER_HELPER(xmlNs)
+PHP_DOM_DEFINE_LIST_EQUALITY_ORDERED_HELPER(xmlNode)
+PHP_DOM_DEFINE_LIST_EQUALITY_UNORDERED_HELPER(xmlNode)
+PHP_DOM_DEFINE_LIST_EQUALITY_UNORDERED_HELPER(xmlNs)
 
 static bool php_dom_node_is_equal_node(const xmlNode *this, const xmlNode *other)
 {
@@ -1535,9 +1560,9 @@ static bool php_dom_node_is_equal_node(const xmlNode *this, const xmlNode *other
 			&& php_dom_node_is_ns_prefix_equal(this, other)
 			&& php_dom_node_is_ns_uri_equal(this, other)
 			/* Check attributes first, then namespace declarations, then children */
-			&& php_dom_node_list_equality_check_xmlNode((const xmlNode *) this->properties, (const xmlNode *) other->properties)
-			&& php_dom_node_list_equality_check_xmlNs(this->nsDef, other->nsDef)
-			&& php_dom_node_list_equality_check_xmlNode(this->children, other->children);
+			&& php_dom_node_list_equality_check_unordered_xmlNode((const xmlNode *) this->properties, (const xmlNode *) other->properties)
+			&& php_dom_node_list_equality_check_unordered_xmlNs(this->nsDef, other->nsDef)
+			&& php_dom_node_list_equality_check_ordered_xmlNode(this->children, other->children);
 	} else if (this->type == XML_DTD_NODE) {
 		/* Note: in the living spec entity declarations and notations are no longer compared because they're considered obsolete. */
 		const xmlDtd *this_dtd = (const xmlDtd *) this;
@@ -1570,7 +1595,7 @@ static bool php_dom_node_is_equal_node(const xmlNode *this, const xmlNode *other
 		const xmlNs *other_ns = (const xmlNs *) other;
 		return xmlStrEqual(this_ns->prefix, other_ns->prefix) && xmlStrEqual(this_ns->href, other_ns->href);
 	} else if (this->type == XML_DOCUMENT_FRAG_NODE || this->type == XML_HTML_DOCUMENT_NODE || this->type == XML_DOCUMENT_NODE) {
-		return php_dom_node_list_equality_check_xmlNode(this->children, other->children);
+		return php_dom_node_list_equality_check_ordered_xmlNode(this->children, other->children);
 	}
 
 	return false;
diff --git a/ext/dom/tests/gh13012.phpt b/ext/dom/tests/gh13012.phpt
new file mode 100644
index 0000000000000..384b43d20099c
--- /dev/null
+++ b/ext/dom/tests/gh13012.phpt
@@ -0,0 +1,37 @@
+--TEST--
+GH-13012 (DOMNode::isEqualNode() is incorrect when attribute order is different)
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = new DOMDocument;
+$dom->loadXML("<root><x a='a' b='b'/><x b='b' a='a'/><x b='b' a='a' c='c'/></root>");
+
+foreach ($dom->getElementsByTagName('x') as $x1) {
+    foreach ($dom->getElementsByTagName('x') as $x2) {
+        echo "Comparing ", $dom->saveXML($x1), " with ", $dom->saveXML($x2), "\n";
+        var_dump($x1->isEqualNode($x2));
+    }
+}
+
+?>
+--EXPECT--
+Comparing <x a="a" b="b"/> with <x a="a" b="b"/>
+bool(true)
+Comparing <x a="a" b="b"/> with <x b="b" a="a"/>
+bool(true)
+Comparing <x a="a" b="b"/> with <x b="b" a="a" c="c"/>
+bool(false)
+Comparing <x b="b" a="a"/> with <x a="a" b="b"/>
+bool(true)
+Comparing <x b="b" a="a"/> with <x b="b" a="a"/>
+bool(true)
+Comparing <x b="b" a="a"/> with <x b="b" a="a" c="c"/>
+bool(false)
+Comparing <x b="b" a="a" c="c"/> with <x a="a" b="b"/>
+bool(false)
+Comparing <x b="b" a="a" c="c"/> with <x b="b" a="a"/>
+bool(false)
+Comparing <x b="b" a="a" c="c"/> with <x b="b" a="a" c="c"/>
+bool(true)
diff --git a/ext/dom/tests/gh13012_ns.phpt b/ext/dom/tests/gh13012_ns.phpt
new file mode 100644
index 0000000000000..33edbe91790d8
--- /dev/null
+++ b/ext/dom/tests/gh13012_ns.phpt
@@ -0,0 +1,37 @@
+--TEST--
+GH-13012 (DOMNode::isEqualNode() is incorrect when attribute order is different - ns variation)
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = new DOMDocument;
+$dom->loadXML("<root><x/><x xmlns:a=\"urn:a\" xmlns:b=\"urn:b\"/><x xmlns:b=\"urn:b\" xmlns:a=\"urn:a\"/></root>");
+
+foreach ($dom->getElementsByTagName('x') as $x1) {
+    foreach ($dom->getElementsByTagName('x') as $x2) {
+        echo "Comparing ", $dom->saveXML($x1), " with ", $dom->saveXML($x2), "\n";
+        var_dump($x1->isEqualNode($x2));
+    }
+}
+
+?>
+--EXPECT--
+Comparing <x/> with <x/>
+bool(true)
+Comparing <x/> with <x xmlns:a="urn:a" xmlns:b="urn:b"/>
+bool(false)
+Comparing <x/> with <x xmlns:b="urn:b" xmlns:a="urn:a"/>
+bool(false)
+Comparing <x xmlns:a="urn:a" xmlns:b="urn:b"/> with <x/>
+bool(false)
+Comparing <x xmlns:a="urn:a" xmlns:b="urn:b"/> with <x xmlns:a="urn:a" xmlns:b="urn:b"/>
+bool(true)
+Comparing <x xmlns:a="urn:a" xmlns:b="urn:b"/> with <x xmlns:b="urn:b" xmlns:a="urn:a"/>
+bool(true)
+Comparing <x xmlns:b="urn:b" xmlns:a="urn:a"/> with <x/>
+bool(false)
+Comparing <x xmlns:b="urn:b" xmlns:a="urn:a"/> with <x xmlns:a="urn:a" xmlns:b="urn:b"/>
+bool(true)
+Comparing <x xmlns:b="urn:b" xmlns:a="urn:a"/> with <x xmlns:b="urn:b" xmlns:a="urn:a"/>
+bool(true)