diff --git a/SDT/schema4.0/etc/domain.rnc b/SDT/schema4.0/etc/domain.rnc
index 88a42191f1c0dae9f8dd5363c76a701b8d48de07..d30de5934d3309fa6f6d272cd89004fb28e0053f 100644
--- a/SDT/schema4.0/etc/domain.rnc
+++ b/SDT/schema4.0/etc/domain.rnc
@@ -47,7 +47,7 @@ DataTypeDef =
     attribute name { text }?,
     attribute unitOfMeasure { text }?,
     DocDef,
-    (StructType | ArrayType | SimpleType),
+    (StructType | ArrayType | SimpleType | EnumType),
     ConstraintsDef?
   }
 StructType = element Struct { DataTypeDef+ }
@@ -56,6 +56,7 @@ SimpleType =
   element SimpleType {
     attribute type { BasicType }
   }
+EnumType = element EnumType { EnumValueDef+ }
 BasicType =
   "integer"
   | "boolean"
@@ -69,6 +70,13 @@ BasicType =
   | "blob"
   | "uri"
   | "void"
+EnumValueDef =
+  element EnumValue {
+    attribute name { text },
+    attribute value { text },
+    attribute type { BasicType }?,
+    DocDef
+  }
 ConstraintsDef =
   element Constraints {
     element Constraint {
diff --git a/SDT/schema4.0/src/domain.rng b/SDT/schema4.0/src/domain.rng
index 3f5e1291d3be0061700134a37cacb839e50d30d4..188fa93b07e2dbda2783c6bbd7720ddf51993ae5 100644
--- a/SDT/schema4.0/src/domain.rng
+++ b/SDT/schema4.0/src/domain.rng
@@ -121,6 +121,7 @@
 				<ref name="StructType" />
 				<ref name="ArrayType" />
 				<ref name="SimpleType" />
+				<ref name="EnumType" />
 			</choice>
 			<optional>
 				<ref name="ConstraintsDef"/>
@@ -152,6 +153,15 @@
 			</attribute>
 		</element>
 	</define>
+	
+
+	<define name="EnumType">
+		<element name="EnumType">
+			<oneOrMore>
+				<ref name="EnumValueDef" />
+			</oneOrMore>
+		</element>
+	</define>
 
 
 	<define name="BasicType">
@@ -172,6 +182,23 @@
 	</define>
 
 
+	<define name="EnumValueDef">
+		<element name="EnumValue">
+			<attribute name="name">
+				<text/>
+			</attribute>
+			<attribute name="value">
+				<text/>
+			</attribute>
+			<optional>
+				<attribute name="type">
+					<ref name="BasicType"/>
+				</attribute>
+			</optional>
+			<ref name="DocDef"/>
+		</element>
+	</define>
+
 	<define name="ConstraintsDef">
 		<element name="Constraints">
 			<oneOrMore>
diff --git a/SDT/schema4.0/src/domain.xsd b/SDT/schema4.0/src/domain.xsd
index 02696bf77a96783fdf7f509a34ccedca948287f4..72a77173bbc5cc6eb1e70d36642dc1e22ea44119 100644
--- a/SDT/schema4.0/src/domain.xsd
+++ b/SDT/schema4.0/src/domain.xsd
@@ -95,6 +95,7 @@
           <xs:element ref="Struct"/>
           <xs:element ref="Array"/>
           <xs:element ref="SimpleType"/>
+          <xs:element ref="EnumType"/>
         </xs:choice>
         <xs:element minOccurs="0" ref="Constraints"/>
       </xs:sequence>
@@ -121,6 +122,13 @@
       <xs:attribute name="type" use="required" type="BasicType"/>
     </xs:complexType>
   </xs:element>
+  <xs:element name="EnumType">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element maxOccurs="unbounded" ref="EnumValue"/>
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
   <xs:simpleType name="BasicType">
     <xs:restriction base="xs:token">
       <xs:enumeration value="integer"/>
@@ -137,6 +145,14 @@
       <xs:enumeration value="void"/>
     </xs:restriction>
   </xs:simpleType>
+  <xs:element name="EnumValue">
+    <xs:complexType>
+      <xs:group ref="DocDef"/>
+      <xs:attribute name="name" use="required"/>
+      <xs:attribute name="value" use="required"/>
+      <xs:attribute name="type" type="BasicType"/>
+    </xs:complexType>
+  </xs:element>
   <xs:element name="Constraints">
     <xs:complexType>
       <xs:sequence>
diff --git a/SDT/schema4.0/test/enumtype-test.xml b/SDT/schema4.0/test/enumtype-test.xml
new file mode 100644
index 0000000000000000000000000000000000000000..2b7a418def6cb62db55e0737aabda3c6644a71d4
--- /dev/null
+++ b/SDT/schema4.0/test/enumtype-test.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!-- Test the void BasicType -->
+
+<Domain id="enumtype-test" xmlns="http://homegatewayinitiative.org/xml/dal/4.0" xmlns:xi="http://www.w3.org/2001/XInclude">
+	<ModuleClasses>
+		<ModuleClass name="TestEnumType">
+			<Data>
+				<DataPoint name="TestEnumTypeDataPoint" writable="true">
+					<DataType>
+						<EnumType>
+							<EnumValue name="red" value="1" type="integer" />
+							<EnumValue name="green" value="2" />
+							<EnumValue name="blue" value="3" />
+						</EnumType>
+					</DataType>
+				</DataPoint>
+			</Data>
+		</ModuleClass>
+	</ModuleClasses>
+</Domain>
\ No newline at end of file