diff --git a/etc/cyclonedds.xsd b/etc/cyclonedds.xsd
index 7e2beed..da6da80 100644
--- a/etc/cyclonedds.xsd
+++ b/etc/cyclonedds.xsd
@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
+
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           xmlns="https://cdds.io/config"
+           targetNamespace="https://cdds.io/config"
+           elementFormDefault="qualified">
   <xs:element name="CycloneDDS">
     <xs:annotation>
       <xs:documentation>
diff --git a/src/core/ddsc/tests/config_simple_udp.xml b/src/core/ddsc/tests/config_simple_udp.xml
index c333d64..426fd10 100644
--- a/src/core/ddsc/tests/config_simple_udp.xml
+++ b/src/core/ddsc/tests/config_simple_udp.xml
@@ -1,4 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" ?>
+<?xml-model href="https://raw.githubusercontent.com/eclipse-cyclonedds/cyclonedds/master/etc/cyclonedds.xsd"
+        schematypens="http://www.w3.org/2001/XMLSchema" ?>
 <!--
   Copyright(c) 2006 to 2018 ADLINK Technology Limited and others
 
@@ -10,7 +12,7 @@
 
   SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 -->
-<CycloneDDS>
+<CycloneDDS xmlns="https://cdds.io/config">
   <!-- Simple config-file for testing whether a config-file can be picked up
        correctly. -->
   <Domain id="3">
diff --git a/src/mpt/tests/basic/etc/config_any.xml b/src/mpt/tests/basic/etc/config_any.xml
index 275eb4b..a00f45c 100644
--- a/src/mpt/tests/basic/etc/config_any.xml
+++ b/src/mpt/tests/basic/etc/config_any.xml
@@ -1,3 +1,6 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<?xml-model href="https://raw.githubusercontent.com/eclipse-cyclonedds/cyclonedds/master/etc/cyclonedds.xsd"
+        schematypens="http://www.w3.org/2001/XMLSchema" ?>
 <!--
   Copyright(c) 2006 to 2018 ADLINK Technology Limited and others
 
@@ -9,7 +12,7 @@
 
   SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 -->
-<CycloneDDS>
+<CycloneDDS xmlns="https://cdds.io/config">
   <Domain>
     <Id>any</Id>
   </Domain>
diff --git a/src/mpt/tests/basic/etc/config_specific.xml b/src/mpt/tests/basic/etc/config_specific.xml
index 0532aa0..2dbd678 100644
--- a/src/mpt/tests/basic/etc/config_specific.xml
+++ b/src/mpt/tests/basic/etc/config_specific.xml
@@ -1,3 +1,6 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<?xml-model href="https://raw.githubusercontent.com/eclipse-cyclonedds/cyclonedds/master/etc/cyclonedds.xsd"
+        schematypens="http://www.w3.org/2001/XMLSchema" ?>
 <!--
   Copyright(c) 2006 to 2018 ADLINK Technology Limited and others
 
@@ -9,7 +12,7 @@
 
   SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 -->
-<CycloneDDS>
+<CycloneDDS xmlns="https://cdds.io/config">
   <Domain>
     <Id>${DOMAIN_ID}</Id>
   </Domain>