diff --git a/packages/schematics/angular/migrations/update-12/update-angular-config.ts b/packages/schematics/angular/migrations/update-12/update-angular-config.ts
index b15ac2196d2b..7a4da5035685 100644
--- a/packages/schematics/angular/migrations/update-12/update-angular-config.ts
+++ b/packages/schematics/angular/migrations/update-12/update-angular-config.ts
@@ -7,38 +7,17 @@
  */
 
 import { Rule } from '@angular-devkit/schematics';
-import { updateWorkspace } from '../../utility/workspace';
+import { allTargetOptions, allWorkspaceTargets, updateWorkspace } from '../../utility/workspace';
 
 export default function (): Rule {
   return updateWorkspace(workspace => {
-    const optionsToRemove: Record<string, undefined> = {
-      experimentalRollupPass: undefined,
-    };
-
-    for (const [, project] of workspace.projects) {
-      for (const [, target] of project.targets) {
-        // Only interested in Angular Devkit builders
-        if (!target?.builder.startsWith('@angular-devkit/build-angular')) {
-          continue;
-        }
-
-        // Check options
-        if (target.options) {
-          target.options = {
-            ...optionsToRemove,
-          };
-        }
-
-        // Go through each configuration entry
-        if (!target.configurations) {
-          continue;
-        }
+    for (const [, target] of allWorkspaceTargets(workspace)) {
+      if (!target.builder.startsWith('@angular-devkit/build-angular')) {
+        continue;
+      }
 
-        for (const configurationName of Object.keys(target.configurations)) {
-          target.configurations[configurationName] = {
-            ...optionsToRemove,
-          };
-        }
+      for (const [, options] of allTargetOptions(target)) {
+        delete options.experimentalRollupPass;
       }
     }
   });
diff --git a/packages/schematics/angular/migrations/update-12/update-angular-config_spec.ts b/packages/schematics/angular/migrations/update-12/update-angular-config_spec.ts
index 96101c521936..b3cc6f6c3374 100644
--- a/packages/schematics/angular/migrations/update-12/update-angular-config_spec.ts
+++ b/packages/schematics/angular/migrations/update-12/update-angular-config_spec.ts
@@ -85,6 +85,7 @@ describe(`Migration to update 'angular.json'. ${schematicName}`, () => {
     const { options, configurations } = getBuildTarget(newTree);
 
     expect(options.experimentalRollupPass).toBeUndefined();
+    expect(options.sourceMaps).toBeTrue();
     expect(configurations).toBeDefined();
     expect(configurations?.one.experimentalRollupPass).toBeUndefined();
     expect(configurations?.two.experimentalRollupPass).toBeUndefined();