diff --git a/schematics/ng-update/upgrade-rules/v17/preloader.ts b/schematics/ng-update/upgrade-rules/v17/preloader.ts
index fa7dee6e93..18b1db033f 100644
--- a/schematics/ng-update/upgrade-rules/v17/preloader.ts
+++ b/schematics/ng-update/upgrade-rules/v17/preloader.ts
@@ -9,7 +9,9 @@ export function updatePreloader(): Rule {
     const angularJson = readJSON(tree, DEFAULT_WORKSPACE_PATH);
     const projectNames = Object.keys(angularJson.projects);
     for (const name of projectNames) {
-      run(tree, name, angularJson.projects[name].sourceRoot, context);
+      const sourceRoot = angularJson.projects[name].sourceRoot;
+      fixIndexHtml(tree, name, sourceRoot, context);
+      run(tree, name, sourceRoot, context);
     }
   };
 }
@@ -18,7 +20,21 @@ function addESLintIgnore(tree: Tree): void {
   const filePath = '/.eslintignore';
   if (!tree.exists(filePath)) return;
   const content = tree.readText(filePath);
-  tree.overwrite(filePath, `${content}\n**/src/index.html`);
+  if (!content.includes('**/src/index.html')) {
+    tree.overwrite(filePath, `${content}\n**/src/index.html`);
+  }
+}
+
+function fixIndexHtml(tree: Tree, _: string, sourceRoot: string, __: SchematicContext): void {
+  const indexPath = `${sourceRoot}/index.html`;
+  if (!tree.exists(indexPath)) return;
+
+  let indexContent = tree.readText(indexPath);
+
+  const selfClose = '<app-root />';
+  if (!indexContent.includes(selfClose)) return;
+
+  tree.overwrite(indexPath, indexContent.replace(selfClose, '<app-root></app-root>'));
 }
 
 function run(tree: Tree, name: string, sourceRoot: string, context: SchematicContext): void {
@@ -36,18 +52,20 @@ function run(tree: Tree, name: string, sourceRoot: string, context: SchematicCon
   const appPath = `${sourceRoot}/app/app.component.ts`;
   if (!tree.exists(appPath)) return;
   const appContent = tree.readText(appPath);
+  if (appContent.includes(', stepPreloader')) return;
+
   const appContentLines = appContent.split('\n');
   const importIndex = appContentLines.findIndex(line => line.includes(', VERSION as VERSION_ALAIN'));
-  const eventIndex = appContentLines.findIndex(line => line.includes('this.router.events.subscribe('));
-  const eventEndIndex = appContentLines.findIndex(line => line.includes('if (ev instanceof NavigationEnd) {'));
-  if (importIndex === -1 || eventIndex === -1 || eventEndIndex === -1) return;
+  const addIndex = appContentLines.findIndex(line => line.includes('export class AppComponent'));
+  const callDoneIndex = appContentLines.findIndex(line => line.includes('if (ev instanceof NavigationEnd) {'));
+  if (importIndex === -1 || addIndex === -1 || callDoneIndex === -1) return;
 
   appContentLines[importIndex] = appContentLines[importIndex].replace(
     ', VERSION as VERSION_ALAIN',
     ', VERSION as VERSION_ALAIN, stepPreloader'
   );
-  appContentLines.splice(eventIndex, 0, 'const done = stepPreloader();');
-  appContentLines.splice(eventEndIndex + 2, 0, 'done();');
+  appContentLines.splice(addIndex + 1, 0, 'private donePreloader = stepPreloader();');
+  appContentLines.splice(callDoneIndex + 2, 0, 'this.donePreloader();');
 
   tree.overwrite(appPath, appContentLines.join('\n'));