diff --git a/packages/angular/build/src/builders/unit-test/schema.json b/packages/angular/build/src/builders/unit-test/schema.json
index 403b61a9009b..b0ccd9088cb2 100644
--- a/packages/angular/build/src/builders/unit-test/schema.json
+++ b/packages/angular/build/src/builders/unit-test/schema.json
@@ -21,7 +21,7 @@
     },
     "runnerConfig": {
       "type": ["string", "boolean"],
-      "description": "Specifies the configuration file for the selected test runner. If a string is provided, it will be used as the path to the configuration file. If `true`, the builder will search for a default configuration file (e.g., `vitest.config.ts` or `karma.conf.js`). If `false`, no external configuration file will be used.\\nFor Vitest, this enables advanced options and the use of custom plugins. Please note that while the file is loaded, the Angular team does not provide direct support for its specific contents or any third-party plugins used within it.",
+      "description": "Specifies the configuration file for the selected test runner. If a string is provided, it will be used as the path to the configuration file. If `true`, the builder will search for a default configuration file (e.g., `vitest-base.config.ts` or `karma.conf.js`). If `false`, no external configuration file will be used.\\nFor Vitest, this enables advanced options and the use of custom plugins. Please note that while the file is loaded, the Angular team does not provide direct support for its specific contents or any third-party plugins used within it.",
       "default": false
     },
     "browsers": {
diff --git a/packages/schematics/angular/migrations/migrate-karma-to-vitest/karma-processor.ts b/packages/schematics/angular/migrations/migrate-karma-to-vitest/karma-processor.ts
index 9fc773470c52..e6e96d886781 100644
--- a/packages/schematics/angular/migrations/migrate-karma-to-vitest/karma-processor.ts
+++ b/packages/schematics/angular/migrations/migrate-karma-to-vitest/karma-processor.ts
@@ -158,7 +158,8 @@ export async function processKarmaConfig(
       context.logger.warn(
         `Project "${projectName}" uses a custom Karma configuration file "${karmaConfig}". ` +
           `Tests have been migrated to use Vitest, but you may need to manually migrate custom settings ` +
-          `from this Karma config to a Vitest config (e.g. vitest.config.ts).`,
+          `from this Karma config to a Vitest config (e.g. "vitest-base.config.ts") ` +
+          `and set the "runnerConfig" option to true.`,
       );
       manualMigrationFiles.push(karmaConfig);
     }