diff --git a/ext/dom/node.c b/ext/dom/node.c
index a6f88b5c0f1bb..53e6457ca71d0 100644
--- a/ext/dom/node.c
+++ b/ext/dom/node.c
@@ -20,6 +20,7 @@
 #endif
 
 #include "php.h"
+
 #if defined(HAVE_LIBXML) && defined(HAVE_DOM)
 #include "php_dom.h"
 
@@ -976,6 +977,9 @@ PHP_METHOD(DOMNode, insertBefore)
 			new_child = _php_dom_insert_fragment(parentp, parentp->last, NULL, child, intern, childobj);
 		}
 		if (new_child == NULL) {
+			if (!child->ns && parentp->parent) {
+				xmlSetNs(child, parentp->ns);
+			}
 			new_child = xmlAddChild(parentp, child);
 		}
 	}
@@ -1220,6 +1224,9 @@ PHP_METHOD(DOMNode, appendChild)
 	}
 
 	if (new_child == NULL) {
+		if (!child->ns && nodep->parent) {
+			xmlSetNs(child, nodep->ns);
+		}
 		new_child = xmlAddChild(nodep, child);
 		if (new_child == NULL) {
 			// TODO Convert to Error?
@@ -1668,7 +1675,7 @@ static void dom_canonicalization(INTERNAL_FUNCTION_PARAMETERS, int mode) /* {{{
 		buf = xmlAllocOutputBuffer(NULL);
 	}
 
-    if (buf != NULL) {
+	if (buf != NULL) {
 		ret = xmlC14NDocSaveTo(docp, nodeset, exclusive, inclusive_ns_prefixes,
 			with_comments, buf);
 	}
@@ -1683,9 +1690,9 @@ static void dom_canonicalization(INTERNAL_FUNCTION_PARAMETERS, int mode) /* {{{
 		xmlXPathFreeContext(ctxp);
 	}
 
-    if (buf == NULL || ret < 0) {
-        RETVAL_FALSE;
-    } else {
+	if (buf == NULL || ret < 0) {
+		RETVAL_FALSE;
+	} else {
 		if (mode == 0) {
 #ifdef LIBXML2_NEW_BUFFER
 			ret = xmlOutputBufferGetSize(buf);
@@ -1702,7 +1709,7 @@ static void dom_canonicalization(INTERNAL_FUNCTION_PARAMETERS, int mode) /* {{{
 				RETVAL_EMPTY_STRING();
 			}
 		}
-    }
+	}
 
 	if (buf) {
 		int bytes;
diff --git a/ext/dom/tests/bug81468.phpt b/ext/dom/tests/bug81468.phpt
new file mode 100644
index 0000000000000..5900ca0ff6afd
--- /dev/null
+++ b/ext/dom/tests/bug81468.phpt
@@ -0,0 +1,175 @@
+--TEST--
+Bug #81468 (Inconsistent default namespace inheritance)
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+?>
+--FILE--
+<?php
+$dom = new \DOMDocument();
+$dom
+  ->appendChild($dom->createElementNS('some:namespace', 'foo'))
+  ->appendChild($dom->createElement('bar'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n\n";
+
+
+$dom = new \DOMDocument();
+$dom
+  ->appendChild($dom->createElementNS('some:namespace', 'foo'))
+  ->appendChild($dom->createElementNS('some:namespace_test', 'bar'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom
+  ->appendChild($dom->createElement('bar'))
+  ->appendChild($dom->createElementNS('some:namespace', 'foo'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/bar/n:foo')) . " should be 1\n";
+echo count($xpath->query('/bar/foo')) . " should be 0\n\n";
+
+
+
+$dom = new \DOMDocument();
+$dom
+  ->appendChild($dom->createElementNS('some:namespace', 'foo'))
+  ->appendChild($dom->createElement('bar'))
+  ->appendChild($dom->createElement('baz'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/n:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar/n:baz')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/n:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar/n:baz')) . " should be 1\n\n";
+
+
+$dom = new \DOMDocument();
+$dom
+  ->appendChild($dom->createElementNS('some:namespace', 'foo'))
+  ->appendChild($dom->createElementNS('some:namespace_test', 'bar'))
+  ->appendChild($dom->createElement('baz'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/m:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar/m:baz')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/m:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar/m:baz')) . " should be 1\n\n";
+
+?>
+--EXPECT--
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar/></foo>
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar/></foo>
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"/></foo>
+0 should be 0
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"/></foo>
+0 should be 0
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<bar><foo xmlns="some:namespace"/></bar>
+1 should be 1
+0 should be 0
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
diff --git a/ext/dom/tests/bug81468_2.phpt b/ext/dom/tests/bug81468_2.phpt
new file mode 100644
index 0000000000000..9a3a89267792e
--- /dev/null
+++ b/ext/dom/tests/bug81468_2.phpt
@@ -0,0 +1,175 @@
+--TEST--
+Bug #81468 (Inconsistent default namespace inheritance)
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+?>
+--FILE--
+<?php
+$dom = new \DOMDocument();
+$dom
+  ->insertBefore($dom->createElementNS('some:namespace', 'foo'))
+  ->insertBefore($dom->createElement('bar'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n\n";
+
+
+$dom = new \DOMDocument();
+$dom
+  ->insertBefore($dom->createElementNS('some:namespace', 'foo'))
+  ->insertBefore($dom->createElementNS('some:namespace_test', 'bar'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom
+  ->insertBefore($dom->createElement('bar'))
+  ->insertBefore($dom->createElementNS('some:namespace', 'foo'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/bar/n:foo')) . " should be 1\n";
+echo count($xpath->query('/bar/foo')) . " should be 0\n\n";
+
+
+
+$dom = new \DOMDocument();
+$dom
+  ->insertBefore($dom->createElementNS('some:namespace', 'foo'))
+  ->insertBefore($dom->createElement('bar'))
+  ->insertBefore($dom->createElement('baz'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/n:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar/n:baz')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/n:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/n:bar/n:baz')) . " should be 1\n\n";
+
+
+$dom = new \DOMDocument();
+$dom
+  ->insertBefore($dom->createElementNS('some:namespace', 'foo'))
+  ->insertBefore($dom->createElementNS('some:namespace_test', 'bar'))
+  ->insertBefore($dom->createElement('baz'));
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/m:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar/m:baz')) . " should be 1\n\n";
+
+$dom = new \DOMDocument();
+$dom->loadXml($xml);
+echo ($xml = $dom->saveXML());
+
+$xpath = new \DOMXPath($dom);
+$xpath->registerNamespace('n', 'some:namespace');
+$xpath->registerNamespace('m', 'some:namespace_test');
+echo count($xpath->query('/n:foo/bar')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar')) . " should be 1\n";
+echo count($xpath->query('/n:foo/m:bar/baz')) . " should be 0\n";
+echo count($xpath->query('/n:foo/m:bar/m:baz')) . " should be 1\n\n";
+
+?>
+--EXPECT--
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar/></foo>
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar/></foo>
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"/></foo>
+0 should be 0
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"/></foo>
+0 should be 0
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<bar><foo xmlns="some:namespace"/></bar>
+1 should be 1
+0 should be 0
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1
+
+<?xml version="1.0"?>
+<foo xmlns="some:namespace"><bar xmlns="some:namespace_test"><baz/></bar></foo>
+0 should be 0
+1 should be 1
+0 should be 0
+1 should be 1