diff --git a/ext/dom/inner_outer_html_mixin.c b/ext/dom/inner_outer_html_mixin.c
index 4655878c533fb..7dc1199fdebb9 100644
--- a/ext/dom/inner_outer_html_mixin.c
+++ b/ext/dom/inner_outer_html_mixin.c
@@ -392,12 +392,15 @@ zend_result dom_element_outer_html_read(dom_object *obj, zval *retval)
 	element.doc = this->doc;
 
 	xmlNodePtr old_parent = this->parent;
+	xmlNodePtr old_next = this->next;
 	this->parent = &element;
+	this->next = NULL;
 
 	/* 2. Return the result of running fragment serializing algorithm steps with element and true. */
 	zend_string *serialization = dom_element_html_fragment_serialize(obj, &element);
 
 	this->parent = old_parent;
+	this->next = old_next;
 
 	if (serialization == NULL) {
 		return FAILURE;
diff --git a/ext/dom/tests/gh16356.phpt b/ext/dom/tests/gh16356.phpt
new file mode 100644
index 0000000000000..ad09c2681806e
--- /dev/null
+++ b/ext/dom/tests/gh16356.phpt
@@ -0,0 +1,139 @@
+--TEST--
+GH-16356 (Segmentation fault with $outerHTML and next node)
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = Dom\HTMLDocument::createEmpty();
+$dom->append($dom->createElement("container"));
+$e1 = $dom->documentElement->appendChild($dom->createElementNS("urn:example1", "example:foo"));
+$e2 = $dom->documentElement->appendChild($dom->createElementNS("urn:example2", "example:foo"));
+var_dump($e1, $e2);
+
+?>
+--EXPECT--
+object(Dom\Element)#3 (30) {
+  ["namespaceURI"]=>
+  string(12) "urn:example1"
+  ["prefix"]=>
+  string(7) "example"
+  ["localName"]=>
+  string(3) "foo"
+  ["tagName"]=>
+  string(11) "example:foo"
+  ["id"]=>
+  string(0) ""
+  ["className"]=>
+  string(0) ""
+  ["classList"]=>
+  string(22) "(object value omitted)"
+  ["attributes"]=>
+  string(22) "(object value omitted)"
+  ["firstElementChild"]=>
+  NULL
+  ["lastElementChild"]=>
+  NULL
+  ["childElementCount"]=>
+  int(0)
+  ["previousElementSibling"]=>
+  NULL
+  ["nextElementSibling"]=>
+  string(22) "(object value omitted)"
+  ["innerHTML"]=>
+  string(0) ""
+  ["outerHTML"]=>
+  string(27) "<example:foo></example:foo>"
+  ["substitutedNodeValue"]=>
+  string(0) ""
+  ["nodeType"]=>
+  int(1)
+  ["nodeName"]=>
+  string(11) "example:foo"
+  ["baseURI"]=>
+  string(11) "about:blank"
+  ["isConnected"]=>
+  bool(true)
+  ["ownerDocument"]=>
+  string(22) "(object value omitted)"
+  ["parentNode"]=>
+  string(22) "(object value omitted)"
+  ["parentElement"]=>
+  string(22) "(object value omitted)"
+  ["childNodes"]=>
+  string(22) "(object value omitted)"
+  ["firstChild"]=>
+  NULL
+  ["lastChild"]=>
+  NULL
+  ["previousSibling"]=>
+  NULL
+  ["nextSibling"]=>
+  string(22) "(object value omitted)"
+  ["nodeValue"]=>
+  NULL
+  ["textContent"]=>
+  string(0) ""
+}
+object(Dom\Element)#4 (30) {
+  ["namespaceURI"]=>
+  string(12) "urn:example2"
+  ["prefix"]=>
+  string(7) "example"
+  ["localName"]=>
+  string(3) "foo"
+  ["tagName"]=>
+  string(11) "example:foo"
+  ["id"]=>
+  string(0) ""
+  ["className"]=>
+  string(0) ""
+  ["classList"]=>
+  string(22) "(object value omitted)"
+  ["attributes"]=>
+  string(22) "(object value omitted)"
+  ["firstElementChild"]=>
+  NULL
+  ["lastElementChild"]=>
+  NULL
+  ["childElementCount"]=>
+  int(0)
+  ["previousElementSibling"]=>
+  string(22) "(object value omitted)"
+  ["nextElementSibling"]=>
+  NULL
+  ["innerHTML"]=>
+  string(0) ""
+  ["outerHTML"]=>
+  string(27) "<example:foo></example:foo>"
+  ["substitutedNodeValue"]=>
+  string(0) ""
+  ["nodeType"]=>
+  int(1)
+  ["nodeName"]=>
+  string(11) "example:foo"
+  ["baseURI"]=>
+  string(11) "about:blank"
+  ["isConnected"]=>
+  bool(true)
+  ["ownerDocument"]=>
+  string(22) "(object value omitted)"
+  ["parentNode"]=>
+  string(22) "(object value omitted)"
+  ["parentElement"]=>
+  string(22) "(object value omitted)"
+  ["childNodes"]=>
+  string(22) "(object value omitted)"
+  ["firstChild"]=>
+  NULL
+  ["lastChild"]=>
+  NULL
+  ["previousSibling"]=>
+  string(22) "(object value omitted)"
+  ["nextSibling"]=>
+  NULL
+  ["nodeValue"]=>
+  NULL
+  ["textContent"]=>
+  string(0) ""
+}