diff --git a/data/menu.xml b/data/menu.xml
index 3f070737..50cabea9 100644
--- a/data/menu.xml
+++ b/data/menu.xml
@@ -2,7 +2,7 @@
 
 <openbox_menu xmlns="http://openbox.org/"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-        xsi:schemaLocation="http://openbox.org/">
+        xsi:schemaLocation="http://openbox.org/4.0/menu">
 
 <menu id="games-menu" label="Games">
   <item label="Crack-Attack">
diff --git a/data/menu.xsd b/data/menu.xsd
index 0342687d..ebf236b6 100644
--- a/data/menu.xsd
+++ b/data/menu.xsd
@@ -15,8 +15,8 @@
          fix some capitalization
 -->
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
-    targetNamespace="http://openbox.org/"
-    xmlns:ob="http://openbox.org/"
+    targetNamespace="http://openbox.org/4.0/menu"
+    xmlns:ob="http://openbox.org/4.0/menu"
     elementFormDefault="qualified">
     <!--
          root node
diff --git a/data/rc.xml b/data/rc.xml
index 515acffa..333ac0a0 100644
--- a/data/rc.xml
+++ b/data/rc.xml
@@ -5,7 +5,7 @@
 
 <openbox_config xmlns="http://openbox.org/"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-        xsi:schemaLocation="http://openbox.org/">
+        xsi:schemaLocation="http://openbox.org/4.0/rc">
 
 <resistance>
   <strength>10</strength>
diff --git a/data/rc.xsd b/data/rc.xsd
index a4397258..95c32134 100644
--- a/data/rc.xsd
+++ b/data/rc.xsd
@@ -55,8 +55,8 @@
          Add the place attribute for fonts
 -->
 <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
-    targetNamespace="http://openbox.org/"
-    xmlns:ob="http://openbox.org/"
+    targetNamespace="http://openbox.org/4.0/rc"
+    xmlns:ob="http://openbox.org/4.0/rc"
     elementFormDefault="qualified">
     <!--
          root node
diff --git a/data/themerc.xsd b/data/themerc.xsd
index ae93ad90..209d52ac 100755
--- a/data/themerc.xsd
+++ b/data/themerc.xsd
@@ -1,8 +1,8 @@
 <?xml version="1.0"?>
 
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
-    targetNamespace="http://openbox.org/themerc"
-    xmlns:obt="http://openbox.org/themerc"
+    targetNamespace="http://openbox.org/4.0/themerc"
+    xmlns:obt="http://openbox.org/4.0/themerc"
     elementFormDefault="qualified"
     version="1.0">
 
diff --git a/themes/Artwiz-boxed/openbox-3/themerc.xml b/themes/Artwiz-boxed/openbox-3/themerc.xml
index 2431706c..16903c31 100644
--- a/themes/Artwiz-boxed/openbox-3/themerc.xml
+++ b/themes/Artwiz-boxed/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Bear2/openbox-3/themerc.xml b/themes/Bear2/openbox-3/themerc.xml
index bca1b0b5..7357cd37 100644
--- a/themes/Bear2/openbox-3/themerc.xml
+++ b/themes/Bear2/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Clearlooks-Olive/openbox-3/themerc.xml b/themes/Clearlooks-Olive/openbox-3/themerc.xml
index 8f8abbbf..c2a1f5f4 100644
--- a/themes/Clearlooks-Olive/openbox-3/themerc.xml
+++ b/themes/Clearlooks-Olive/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Clearlooks/openbox-3/themerc.xml b/themes/Clearlooks/openbox-3/themerc.xml
index 057d5623..adfe4159 100644
--- a/themes/Clearlooks/openbox-3/themerc.xml
+++ b/themes/Clearlooks/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Mikachu/openbox-3/themerc.xml b/themes/Mikachu/openbox-3/themerc.xml
index dbb45611..1b9d52f0 100644
--- a/themes/Mikachu/openbox-3/themerc.xml
+++ b/themes/Mikachu/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Natura/openbox-3/themerc.xml b/themes/Natura/openbox-3/themerc.xml
index 6ba88e16..3a13bd10 100644
--- a/themes/Natura/openbox-3/themerc.xml
+++ b/themes/Natura/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Orang/openbox-3/themerc.xml b/themes/Orang/openbox-3/themerc.xml
index 85254827..4e312f62 100644
--- a/themes/Orang/openbox-3/themerc.xml
+++ b/themes/Orang/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/themes/Syscrash/openbox-3/themerc.xml b/themes/Syscrash/openbox-3/themerc.xml
index 3df8a080..e5dc59b6 100644
--- a/themes/Syscrash/openbox-3/themerc.xml
+++ b/themes/Syscrash/openbox-3/themerc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<openbox_theme engine="box" version="1" xmlns="http://openbox.org/themerc">
+<openbox_theme engine="box" version="1" xmlns="http://openbox.org/4.0/themerc">
   <about>
     <author></author>
     <email></email>
diff --git a/tools/themetoxml/themetoxml.c b/tools/themetoxml/themetoxml.c
index d5fee29f..bdb331b8 100644
--- a/tools/themetoxml/themetoxml.c
+++ b/tools/themetoxml/themetoxml.c
@@ -325,7 +325,7 @@ int main(int argc, char **argv)
     xmlSetProp(root, (const xmlChar*)"engine", (const xmlChar*)"box");
     xmlSetProp(root, (const xmlChar*)"version", (const xmlChar*)"1");
     xmlSetProp(root, (const xmlChar*)"xmlns",
-               (const xmlChar*)"http://openbox.org/themerc");
+               (const xmlChar*)"http://openbox.org/4.0/themerc");
     CONT2("about", "author", "");
     CONT2("about", "email", "");
     CONT2("about", "webpage", "");