diff --git a/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs b/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs
index 77b2ca3a9..c43af04ba 100644
--- a/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs
+++ b/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs
@@ -405,8 +405,8 @@ public void CannotBuildWithV3LikeUIRef()
 
         private static void Build(string[] args)
         {
-            var result = WixRunner.Execute(args)
-                                  .AssertSuccess();
+            var result = WixRunner.Execute(args);
+            result.AssertSuccess();
         }
 
         private static void BuildX64(string[] args)
diff --git a/src/ext/UI/wixlib/Common.wxs b/src/ext/UI/wixlib/Common.wxs
index bfaa44b83..f95d4d0ec 100644
--- a/src/ext/UI/wixlib/Common.wxs
+++ b/src/ext/UI/wixlib/Common.wxs
@@ -9,7 +9,7 @@
         <Binary Id="WixUI_Ico_Info" SourceFile="!(wix.WixUIInfoIco=$(var.infoIco))" />
         <Binary Id="WixUI_Bmp_New" SourceFile="!(wix.WixUINewIco=$(var.newIco))" />
         <Binary Id="WixUI_Bmp_Up" SourceFile="!(wix.WixUIUpIco=$(var.upIco))" />
-        <WixVariable Id="WixUICostingPopupOptOut" Value="1" Overridable="yes" />
+        <WixVariable Id="virtual WixUICostingPopupOptOut" Value="1" />
 
         <UI Id="WixUI_Common">
             <!-- ui text -->
diff --git a/src/ext/UI/wixlib/ExitDialog.wxs b/src/ext/UI/wixlib/ExitDialog.wxs
index 8f7dec1fc..ab6aafabf 100644
--- a/src/ext/UI/wixlib/ExitDialog.wxs
+++ b/src/ext/UI/wixlib/ExitDialog.wxs
@@ -17,11 +17,11 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="ExitDialog" OnExit="success" Overridable="yes" />
+                <Show Dialog="virtual ExitDialog" OnExit="success" />
             </InstallUISequence>
 
             <AdminUISequence>
-                <Show Dialog="ExitDialog" OnExit="success" Overridable="yes" />
+                <Show Dialog="virtual ExitDialog" OnExit="success" />
             </AdminUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/FatalError.wxs b/src/ext/UI/wixlib/FatalError.wxs
index a383b9b3e..2a8ff1999 100644
--- a/src/ext/UI/wixlib/FatalError.wxs
+++ b/src/ext/UI/wixlib/FatalError.wxs
@@ -17,11 +17,11 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="FatalError" OnExit="error" Overridable="yes" />
+                <Show Dialog="virtual FatalError" OnExit="error" />
             </InstallUISequence>
 
             <AdminUISequence>
-                <Show Dialog="FatalError" OnExit="error" Overridable="yes" />
+                <Show Dialog="virtual FatalError" OnExit="error" />
             </AdminUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/MaintenanceWelcomeDlg.wxs b/src/ext/UI/wixlib/MaintenanceWelcomeDlg.wxs
index 7208aff37..a6ee7fb15 100644
--- a/src/ext/UI/wixlib/MaintenanceWelcomeDlg.wxs
+++ b/src/ext/UI/wixlib/MaintenanceWelcomeDlg.wxs
@@ -19,7 +19,7 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="MaintenanceWelcomeDlg" Before="ProgressDlg" Overridable="yes" Condition="Installed AND NOT RESUME AND NOT Preselected AND NOT PATCH" />
+                <Show Dialog="virtual MaintenanceWelcomeDlg" Before="ProgressDlg" Condition="Installed AND NOT RESUME AND NOT Preselected AND NOT PATCH" />
             </InstallUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/PrepareDlg.wxs b/src/ext/UI/wixlib/PrepareDlg.wxs
index 1b22b04ff..4030472bb 100644
--- a/src/ext/UI/wixlib/PrepareDlg.wxs
+++ b/src/ext/UI/wixlib/PrepareDlg.wxs
@@ -23,7 +23,7 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="PrepareDlg" Before="AppSearch" Overridable="yes" />
+                <Show Dialog="virtual PrepareDlg" Before="AppSearch" />
             </InstallUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/ProgressDlg.wxs b/src/ext/UI/wixlib/ProgressDlg.wxs
index 057b104f8..e62ef1a80 100644
--- a/src/ext/UI/wixlib/ProgressDlg.wxs
+++ b/src/ext/UI/wixlib/ProgressDlg.wxs
@@ -34,7 +34,7 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="ProgressDlg" Before="ExecuteAction" Overridable="yes" />
+                <Show Dialog="virtual ProgressDlg" Before="ExecuteAction" />
             </InstallUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/ResumeDlg.wxs b/src/ext/UI/wixlib/ResumeDlg.wxs
index 67e1cc582..a241e70de 100644
--- a/src/ext/UI/wixlib/ResumeDlg.wxs
+++ b/src/ext/UI/wixlib/ResumeDlg.wxs
@@ -32,7 +32,7 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="ResumeDlg" Before="ProgressDlg" Overridable="yes" Condition="Installed AND (RESUME OR Preselected)" />
+                <Show Dialog="virtual ResumeDlg" Before="ProgressDlg" Condition="Installed AND (RESUME OR Preselected)" />
             </InstallUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/UserExit.wxs b/src/ext/UI/wixlib/UserExit.wxs
index 7c3a07ed1..dc05136ff 100644
--- a/src/ext/UI/wixlib/UserExit.wxs
+++ b/src/ext/UI/wixlib/UserExit.wxs
@@ -17,11 +17,11 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="UserExit" OnExit="cancel" Overridable="yes" />
+                <Show Dialog="virtual UserExit" OnExit="cancel" />
             </InstallUISequence>
 
             <AdminUISequence>
-                <Show Dialog="UserExit" OnExit="cancel" Overridable="yes" />
+                <Show Dialog="virtual UserExit" OnExit="cancel" />
             </AdminUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/WelcomeDlg.wxs b/src/ext/UI/wixlib/WelcomeDlg.wxs
index bb13f1dcf..b60933b9e 100644
--- a/src/ext/UI/wixlib/WelcomeDlg.wxs
+++ b/src/ext/UI/wixlib/WelcomeDlg.wxs
@@ -20,7 +20,7 @@
             </Dialog>
 
             <InstallUISequence>
-                <Show Dialog="WelcomeDlg" Before="ProgressDlg" Overridable="yes" Condition="NOT Installed OR PATCH" />
+                <Show Dialog="virtual WelcomeDlg" Before="ProgressDlg" Condition="NOT Installed OR PATCH" />
             </InstallUISequence>
         </UI>
     </Fragment>
diff --git a/src/ext/UI/wixlib/WelcomeEulaDlg.wxs b/src/ext/UI/wixlib/WelcomeEulaDlg.wxs
index 4b389ac65..ee01d29a3 100644
--- a/src/ext/UI/wixlib/WelcomeEulaDlg.wxs
+++ b/src/ext/UI/wixlib/WelcomeEulaDlg.wxs
@@ -37,7 +37,7 @@
         </UI>
 
         <InstallUISequence>
-            <Show Dialog="WelcomeEulaDlg" Before="ProgressDlg" Overridable="yes" Condition="NOT Installed" />
+            <Show Dialog="virtual WelcomeEulaDlg" Before="ProgressDlg" Condition="NOT Installed" />
         </InstallUISequence>
     </Fragment>
 </Wix>
diff --git a/src/ext/UI/wixlib/WixUI_Advanced.wxs b/src/ext/UI/wixlib/WixUI_Advanced.wxs
index bab05ec94..4f8bfa0cf 100644
--- a/src/ext/UI/wixlib/WixUI_Advanced.wxs
+++ b/src/ext/UI/wixlib/WixUI_Advanced.wxs
@@ -8,7 +8,7 @@ installs, install path, and features.
 WiX variables used:
  - WixUISupportPerMachine
  - WixUISupportPerUser
- 
+
 Todo:
  - Clicking Install doesn't work! - APPLICATIONFOLDER isn't set; need to accept another "incoming" property.
  - Replace this dialog set UI fragment with the UI extension.
@@ -33,8 +33,8 @@ Todo:
     <?endforeach?>
 
     <Fragment>
-        <WixVariable Id="WixUISupportPerUser" Value="1" Overridable="yes" />
-        <WixVariable Id="WixUISupportPerMachine" Value="1" Overridable="yes" />
+        <WixVariable Id="virtual WixUISupportPerUser" Value="1" />
+        <WixVariable Id="virtual WixUISupportPerMachine" Value="1" />
 
         <PropertyRef Id="ApplicationFolderName" />
 
@@ -119,7 +119,7 @@ Todo:
         </UI>
 
         <InstallUISequence>
-            <Show Dialog="WelcomeDlg" Before="AdvancedWelcomeEulaDlg" Condition="Installed AND PATCH" />
+            <Show Dialog="override WelcomeDlg" Before="AdvancedWelcomeEulaDlg" Condition="Installed AND PATCH" />
         </InstallUISequence>
 
         <Property Id="WIXUI_INSTALLDIR" Value="APPLICATIONFOLDER" />