diff --git a/src/preprocess.ts b/src/preprocess.ts
index 98bd9a81..6bf91d47 100644
--- a/src/preprocess.ts
+++ b/src/preprocess.ts
@@ -27,8 +27,7 @@ export function preprocess(context: BuildContext) {
 function preprocessWorker(context: BuildContext) {
   const bundlePromise = bundleCoreComponents(context);
   const deepLinksPromise = getBooleanPropertyValue(Constants.ENV_PARSE_DEEPLINKS) ? deepLinking(context) : Promise.resolve();
-  const componentSassPromise = lookUpDefaultIonicComponentPaths(context);
-  return Promise.all([bundlePromise, deepLinksPromise, componentSassPromise])
+  return Promise.all([bundlePromise, deepLinksPromise])
     .then(() => {
       if (context.optimizeJs) {
         return optimization(context, null);
@@ -68,15 +67,3 @@ export function preprocessUpdate(changedFiles: ChangedFile[], context: BuildCont
 
   return Promise.all(promises);
 }
-
-export function lookUpDefaultIonicComponentPaths(context: BuildContext) {
-  const componentsDirGlob = join(getStringPropertyValue(Constants.ENV_VAR_IONIC_ANGULAR_DIR), 'components', '**', '*.scss');
-  const srcDirGlob = join(getStringPropertyValue(Constants.ENV_VAR_SRC_DIR), '**', '*.scss');
-  return globAll([componentsDirGlob, srcDirGlob]).then((results: GlobResult[]) => {
-    const componentPathSet = new Set<string>();
-    results.forEach(result => {
-      componentPathSet.add(result.absolutePath);
-    });
-    context.moduleFiles = Array.from(componentPathSet);
-  });
-}
diff --git a/src/rollup.ts b/src/rollup.ts
index 650fb9df..006408ee 100644
--- a/src/rollup.ts
+++ b/src/rollup.ts
@@ -73,6 +73,17 @@ export function rollupWorker(context: BuildContext, configFile: string): Promise
 
         Logger.debug(`bundle.modules: ${bundle.modules.length}`);
 
+        // set the module files used in this bundle
+        // this reference can be used elsewhere in the build (sass)
+        context.moduleFiles = bundle.modules.map((m) => {
+          // sometimes, Rollup appends weird prefixes to the path like commonjs:proxy
+          const index = m.id.indexOf(sep);
+          if (index >= 0) {
+            return m.id.substring(index);
+          }
+          return m.id;
+        });
+
         // cache our bundle for later use
         if (context.isWatch) {
           cachedBundle = bundle;
@@ -214,4 +225,4 @@ export interface RollupLocationInfo {
   file: string;
   line: number;
   column: number;
-}
\ No newline at end of file
+}
diff --git a/src/webpack.ts b/src/webpack.ts
index fdc7a765..ea33b970 100644
--- a/src/webpack.ts
+++ b/src/webpack.ts
@@ -93,6 +93,23 @@ function webpackBuildComplete(stats: any, context: BuildContext, webpackConfig:
     Logger.debug('Webpack Dependency Map End');
   }
 
+  // set the module files used in this bundle
+  // this reference can be used elsewhere in the build (sass)
+  if (!context.isProd || !context.optimizeJs) {
+    const files: string[] = stats.compilation.modules.map((webpackObj: any) => {
+      if (webpackObj.resource) {
+        return webpackObj.resource;
+      } else {
+        return webpackObj.context;
+      }
+    }).filter((path: string) => {
+      // just make sure the path is not null
+      return path && path.length > 0;
+    });
+
+    context.moduleFiles = files;
+  }
+
   return setBundledFiles(context);
 }
 
@@ -227,4 +244,4 @@ export interface WebpackOutputObject {
 export interface WebpackResolveObject {
   extensions: string[];
   modules: string[];
-}
\ No newline at end of file
+}