diff --git a/__tests__/get-options-overrides.spec.ts b/__tests__/get-options-overrides.spec.ts
index 18d6bab9..45b4fed8 100644
--- a/__tests__/get-options-overrides.spec.ts
+++ b/__tests__/get-options-overrides.spec.ts
@@ -14,7 +14,7 @@ const local = (x: string) => path.resolve(__dirname, x);
 const cacheDir = local("__temp/get-options-overrides");
 
 // filter expects an absolute path and resolve include/exclude to process.cwd() by default: https://github.com/ezolenko/rollup-plugin-typescript2/pull/321#discussion_r873077874
-const filtPath = (path: string) => `${process.cwd()}/${path}`;
+const filtPath = (relPath: string) => path.normalize(`${process.cwd()}/${relPath}`);
 
 afterAll(() => remove(cacheDir));