diff --git a/build/src/main/resources/docs/schema/wildfly-undertow_1_0.xsd b/build/src/main/resources/docs/schema/wildfly-undertow_1_0.xsd
index 302c6f7efc6a..6a185b364bfa 100644
--- a/build/src/main/resources/docs/schema/wildfly-undertow_1_0.xsd
+++ b/build/src/main/resources/docs/schema/wildfly-undertow_1_0.xsd
@@ -304,7 +304,7 @@
     </xs:complexType>
 
     <xs:complexType name="singleSignOnType">
-        <xs:attribute name="domain" type="xs:string" use="required">
+        <xs:attribute name="domain" type="xs:string">
             <xs:annotation>
                 <xs:documentation>
                     <![CDATA[
diff --git a/testsuite/shared/src/main/java/org/jboss/as/test/integration/web/sso/SSOTestBase.java b/testsuite/shared/src/main/java/org/jboss/as/test/integration/web/sso/SSOTestBase.java
index dd1c02da35ba..544372d2c16b 100644
--- a/testsuite/shared/src/main/java/org/jboss/as/test/integration/web/sso/SSOTestBase.java
+++ b/testsuite/shared/src/main/java/org/jboss/as/test/integration/web/sso/SSOTestBase.java
@@ -354,9 +354,7 @@ public static void addSso(ModelControllerClient client) throws Exception {
         final List<ModelNode> updates = new ArrayList<ModelNode>();
 
         // SSO element name must be 'configuration'
-        ModelNode op = createOpNode("subsystem=undertow/server=default-server/host=default-host/setting=single-sign-on", ADD);
-        op.get("domain").set("${jboss.bind.address:127.0.0.1}");
-        updates.add(op);
+        updates.add(createOpNode("subsystem=undertow/server=default-server/host=default-host/setting=single-sign-on", ADD));
 
         applyUpdates(updates, client);
     }
@@ -364,9 +362,7 @@ public static void addSso(ModelControllerClient client) throws Exception {
     public static void removeSso(final ModelControllerClient client) throws Exception {
         final List<ModelNode> updates = new ArrayList<ModelNode>();
 
-        ModelNode op = createOpNode("subsystem=undertow/server=default-server/host=default-host/setting=single-sign-on", REMOVE);
-        op.get("domain").set("${jboss.bind.address:127.0.0.1}");
-        updates.add(op);
+        updates.add(createOpNode("subsystem=undertow/server=default-server/host=default-host/setting=single-sign-on", REMOVE));
 
         applyUpdates(updates, client);
     }
diff --git a/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnAdd.java b/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnAdd.java
index b32b66835346..c108da3f6e53 100644
--- a/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnAdd.java
+++ b/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnAdd.java
@@ -58,8 +58,8 @@ protected void performRuntime(final OperationContext context, final ModelNode op
                 final PathAddress hostAddress = address.subAddress(0, address.size() - 1);
                 final PathAddress serverAddress = hostAddress.subAddress(0, hostAddress.size() - 1);
 
-        final String domain = SingleSignOnDefinition.DOMAIN.resolveModelAttribute(context, model).asString();
-
+        ModelNode domainModelNode = SingleSignOnDefinition.DOMAIN.resolveModelAttribute(context, model);
+        String domain = domainModelNode.isDefined() ? domainModelNode.asString() : null;
         final String serverName = serverAddress.getLastElement().getValue();
         final String hostName = hostAddress.getLastElement().getValue();
         final ServiceName serviceName = UndertowService.ssoServiceName(serverName, hostName);
diff --git a/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnDefinition.java b/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnDefinition.java
index 59c5ab942c97..7457190b1411 100644
--- a/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnDefinition.java
+++ b/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnDefinition.java
@@ -42,6 +42,7 @@
 class SingleSignOnDefinition extends PersistentResourceDefinition {
 
     static final SimpleAttributeDefinition DOMAIN = new SimpleAttributeDefinitionBuilder(Constants.DOMAIN, ModelType.STRING)
+            .setAllowNull(true)
             .setAllowExpression(true)
             .build();
 
diff --git a/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnService.java b/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnService.java
index ca05b9265c15..5b169103f485 100644
--- a/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnService.java
+++ b/undertow/src/main/java/org/wildfly/extension/undertow/SingleSignOnService.java
@@ -51,17 +51,17 @@ public SingleSignOnService(String domain) {
 
     @Override
     public void start(StartContext startContext) {
+        Host host = this.host.getValue();
         SingleSignOnAuthenticationMechanism mechanism = new SingleSignOnAuthenticationMechanism(this.manager.getValue());
-        if (this.domain != null) {
-            mechanism.setDomain(this.domain);
-        }
+        mechanism.setDomain((this.domain != null) ? this.domain : host.getName());
 
-        this.host.getValue().registerAdditionalAuthenticationMechanism(AUTHENTICATION_MECHANISM_NAME, mechanism);
+        host.registerAdditionalAuthenticationMechanism(AUTHENTICATION_MECHANISM_NAME, mechanism);
     }
 
     @Override
     public void stop(StopContext stopContext) {
-        this.host.getValue().unregisterAdditionalAuthenticationMechanism(AUTHENTICATION_MECHANISM_NAME);
+        Host host = this.host.getValue();
+        host.unregisterAdditionalAuthenticationMechanism(AUTHENTICATION_MECHANISM_NAME);
     }
 
     @Override