diff --git a/packages/angular/build/src/builders/unit-test/test-discovery.ts b/packages/angular/build/src/builders/unit-test/test-discovery.ts
index 89d38dbbe787..47bfed884ad3 100644
--- a/packages/angular/build/src/builders/unit-test/test-discovery.ts
+++ b/packages/angular/build/src/builders/unit-test/test-discovery.ts
@@ -65,7 +65,7 @@ export async function findTests(
     });
 
     for (const match of globMatches) {
-      resolvedTestFiles.add(match);
+      resolvedTestFiles.add(toPosixPath(match));
     }
   }
 
@@ -261,15 +261,15 @@ async function resolveStaticPattern(
   for (const infix of TEST_FILE_INFIXES) {
     const potentialSpec = join(dirname(fullPath), `${baseName}${infix}${fileExt}`);
     if (await exists(potentialSpec)) {
-      return { resolved: [potentialSpec], unresolved: [] };
+      return { resolved: [toPosixPath(potentialSpec)], unresolved: [] };
     }
   }
 
   if (await exists(fullPath)) {
-    return { resolved: [fullPath], unresolved: [] };
+    return { resolved: [toPosixPath(fullPath)], unresolved: [] };
   }
 
-  return { resolved: [], unresolved: [pattern] };
+  return { resolved: [], unresolved: [toPosixPath(pattern)] };
 }
 
 /** Checks if a path exists and is a directory. */
diff --git a/tests/legacy-cli/e2e/tests/vitest/absolute-include.ts b/tests/legacy-cli/e2e/tests/vitest/absolute-include.ts
deleted file mode 100644
index 787fe942edbd..000000000000
--- a/tests/legacy-cli/e2e/tests/vitest/absolute-include.ts
+++ /dev/null
@@ -1,12 +0,0 @@
-import assert from 'node:assert/strict';
-import { applyVitestBuilder } from '../../utils/vitest';
-import { ng } from '../../utils/process';
-import path from 'node:path';
-
-export default async function (): Promise<void> {
-  await applyVitestBuilder();
-
-  const { stdout } = await ng('test', '--include', path.resolve('src/app/app.spec.ts'));
-
-  assert.match(stdout, /1 passed/, 'Expected 1 test to pass.');
-}
diff --git a/tests/legacy-cli/e2e/tests/vitest/include.ts b/tests/legacy-cli/e2e/tests/vitest/include.ts
new file mode 100644
index 000000000000..4585194ef3c2
--- /dev/null
+++ b/tests/legacy-cli/e2e/tests/vitest/include.ts
@@ -0,0 +1,14 @@
+import assert from 'node:assert/strict';
+import { applyVitestBuilder } from '../../utils/vitest';
+import { ng } from '../../utils/process';
+import path from 'node:path';
+
+export default async function (): Promise<void> {
+  await applyVitestBuilder();
+
+  const { stdout: stdout1 } = await ng('test', '--include', path.resolve('src/app/app.spec.ts'));
+  assert.match(stdout1, /1 passed/, 'Expected 1 test to pass with absolute include.');
+
+  const { stdout: stdout2 } = await ng('test', '--include', path.normalize('src/app/app.spec.ts'));
+  assert.match(stdout2, /1 passed/, 'Expected 1 test to pass with relative include.');
+}