diff --git a/src/index.ts b/src/index.ts
index 3015472..70c1f83 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3,6 +3,11 @@ import * as d from './declarations';
 import { loadDiagnostic } from './diagnostics';
 import { createResultsId, getRenderOptions, usePlugin } from './util';
 
+/**
+ * Helper type to note which plugin methods are defined for this plugin.
+ */
+type WithRequired<T, K extends keyof T> = T & { [P in K]-?: T[P] };
+
 /**
  * The entrypoint of the Stencil Sass plugin
  *
@@ -13,7 +18,7 @@ import { createResultsId, getRenderOptions, usePlugin } from './util';
  * @param opts options to configure the plugin
  * @return the configured plugin
  */
-export function sass(opts: d.PluginOptions = {}): d.Plugin {
+export function sass(opts: d.PluginOptions = {}): WithRequired<d.Plugin, 'transform'> {
   return {
     name: 'sass',
     pluginType: 'css',
@@ -52,7 +57,9 @@ export function sass(opts: d.PluginOptions = {}): d.Plugin {
               results.code = `/**  sass error${err && err.message ? ': ' + err.message : ''}  **/`;
               resolve(results);
             } else {
-              results.dependencies = Array.from(sassResult.stats.includedFiles);
+              results.dependencies = Array.from(sassResult.stats.includedFiles).map((dep) =>
+                context.sys.normalizePath(dep),
+              );
               results.code = sassResult.css.toString();
 
               // write this css content to memory only so it can be referenced
diff --git a/test/build.spec.ts b/test/build.spec.ts
index d5486ad..e84b933 100644
--- a/test/build.spec.ts
+++ b/test/build.spec.ts
@@ -14,8 +14,10 @@ describe('test build', () => {
         rootDir: '/Users/my/app/',
         srcDir: '/Users/my/app/src/',
       },
-      cache: null,
-      sys: {} as any,
+      cache: null as any,
+      sys: {
+        normalizePath: jest.fn((p: string) => p),
+      } as any,
       fs: {
         readFileSync(filePath: string) {
           return fs.readFileSync(filePath, 'utf8');
@@ -50,6 +52,7 @@ describe('test build', () => {
       path.join(__dirname, 'fixtures', 'scss', 'variables.scss')
     ]);
     expect(results.diagnostics).toEqual(undefined);
+    expect(context.sys.normalizePath).toBeCalledTimes(1)
   });
 
   it('transform, error scss', async () => {