diff --git a/SDT/schema4.0/src/domain.rng b/SDT/schema4.0/src/domain.rng
index b35d73094c626c542ae46af4f4d0dd29963e7d06..8c037eb776689d115a0ec2a4d0ff49c71fec8a16 100644
--- a/SDT/schema4.0/src/domain.rng
+++ b/SDT/schema4.0/src/domain.rng
@@ -168,12 +168,12 @@
 			<value>byte</value>
 			<value>float</value>
 			<value>array</value>
-			<value>enum</value>
 			<value>date</value>
 			<value>time</value>
 			<value>datetime</value>
 			<value>blob</value>
 			<value>uri</value>
+			<value>void</value>
 		</choice>
 	</define>
 
diff --git a/SDT/schema4.0/src/domain.xsd b/SDT/schema4.0/src/domain.xsd
index 1071587ba52303129f853c45257b1fef7a7576e0..a6002259be11ed0c3f00436a2f3f787e19fb1ab6 100644
--- a/SDT/schema4.0/src/domain.xsd
+++ b/SDT/schema4.0/src/domain.xsd
@@ -9,8 +9,8 @@
   - See the license text at [https://opensource.org/licenses/BSD-3-Clause for
   - full details.
 -->
-<xs:schema targetNamespace="http://homegatewayinitiative.org/xml/dal/3.0" 
-	   xmlns="http://homegatewayinitiative.org/xml/dal/3.0" 
+<xs:schema targetNamespace="http://homegatewayinitiative.org/xml/dal/4.0" 
+	   xmlns="http://homegatewayinitiative.org/xml/dal/4.0" 
 	   xmlns:xs="http://www.w3.org/2001/XMLSchema" 
 	  
  elementFormDefault="qualified">
@@ -136,12 +136,12 @@
       <xs:enumeration value="byte"/>
       <xs:enumeration value="float"/>
       <xs:enumeration value="array"/>
-      <xs:enumeration value="enum"/>
       <xs:enumeration value="date"/>
       <xs:enumeration value="time"/>
       <xs:enumeration value="datetime"/>
       <xs:enumeration value="blob"/>
       <xs:enumeration value="uri"/>
+      <xs:enumeration value="void"/>
     </xs:restriction>
   </xs:simpleType>
   <xs:element name="Constraints">
diff --git a/SDT/schema4.0/test/void-test.xml b/SDT/schema4.0/test/void-test.xml
new file mode 100644
index 0000000000000000000000000000000000000000..516bb7f7c405b1d276ce530357cdd5abf52f4743
--- /dev/null
+++ b/SDT/schema4.0/test/void-test.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!-- Test the void BasicType -->
+
+<Domain id="example2.SDT" xmlns="http://homegatewayinitiative.org/xml/dal/4.0" xmlns:xi="http://www.w3.org/2001/XInclude">
+	<Modules>
+		<ModuleClass name="TestVoid">
+			<Actions>
+				<Action name="TestVoidAction">
+					<DataType>
+						<SimpleType type="void"/>
+					</DataType>
+				</Action>
+			</Actions>
+			<Data>
+				<DataPoint name="TestVoidDataPoint" writable="true">
+					<DataType>
+						<SimpleType type="void"/>
+					</DataType>
+				</DataPoint>
+			</Data>
+		</ModuleClass>
+	</Modules>
+</Domain>
\ No newline at end of file