diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 3dd6cc037ab..b07f2d186d8 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -3854,7 +3854,9 @@ xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt)
 {
 	xmltype    *result = NULL;
 
-	if (cur->type != XML_ATTRIBUTE_NODE && cur->type != XML_TEXT_NODE)
+	if (cur->type != XML_ATTRIBUTE_NODE &&
+		cur->type != XML_TEXT_NODE &&
+		cur->type != XML_NAMESPACE_DECL)
 	{
 		void		(*volatile nodefree) (xmlNodePtr) = NULL;
 		volatile xmlBufferPtr buf = NULL;
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 79054b75311..ec30cb76ce4 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -710,6 +710,12 @@ SELECT xpath('root', '<root/>');
  {<root/>}
 (1 row)
 
+SELECT xpath('//namespace::foo', '<root xmlns:foo="http://127.0.0.1"/>');
+       xpath        
+--------------------
+ {http://127.0.0.1}
+(1 row)
+
 -- Round-trip non-ASCII data through xpath().
 DO $$
 DECLARE
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index abf27626a21..684fa070fe4 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -516,6 +516,11 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xpath('root', '<root/>');
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT xpath('//namespace::foo', '<root xmlns:foo="http://127.0.0.1"/>');
+ERROR:  unsupported XML feature
+LINE 1: SELECT xpath('//namespace::foo', '<root xmlns:foo="http://12...
+                                         ^
+DETAIL:  This functionality requires the server to be built with libxml support.
 -- Round-trip non-ASCII data through xpath().
 DO $$
 DECLARE
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 83c5b73d8d3..57c3412d743 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -196,6 +196,7 @@ SELECT xpath('count(//*)=3', '<root><sub/><sub/></root>');
 SELECT xpath('name(/*)', '<root><sub/><sub/></root>');
 SELECT xpath('/nosuchtag', '<root/>');
 SELECT xpath('root', '<root/>');
+SELECT xpath('//namespace::foo', '<root xmlns:foo="http://127.0.0.1"/>');
 
 -- Round-trip non-ASCII data through xpath().
 DO $$