diff --git a/packages/compiler-cli/src/ngtsc/resource/src/loader.ts b/packages/compiler-cli/src/ngtsc/resource/src/loader.ts
index d660e7b4b1..041b8f0594 100644
--- a/packages/compiler-cli/src/ngtsc/resource/src/loader.ts
+++ b/packages/compiler-cli/src/ngtsc/resource/src/loader.ts
@@ -13,7 +13,7 @@ import {ExtendedTsCompilerHost} from '../../core/api';
 import {AbsoluteFsPath, PathSegment, join} from '../../file_system';
 import {getRootDirs} from '../../util/src/typescript';
 
-const CSS_PREPROCESSOR_EXT = /(\.scss|\.less|\.styl)$/;
+const CSS_PREPROCESSOR_EXT = /(\.scss|\.sass|\.less|\.styl)$/;
 
 /**
  * `ResourceLoader` which delegates to a `CompilerHost` resource loading method.
diff --git a/packages/compiler-cli/src/transformers/compiler_host.ts b/packages/compiler-cli/src/transformers/compiler_host.ts
index 739cd38e00..353b1884d8 100644
--- a/packages/compiler-cli/src/transformers/compiler_host.ts
+++ b/packages/compiler-cli/src/transformers/compiler_host.ts
@@ -20,7 +20,7 @@ import {DTS, GENERATED_FILES, isInRootDir, relativeToRootDirs} from './util';
 
 const NODE_MODULES_PACKAGE_NAME = /node_modules\/((\w|-|\.)+|(@(\w|-|\.)+\/(\w|-|\.)+))/;
 const EXT = /(\.ts|\.d\.ts|\.js|\.jsx|\.tsx)$/;
-const CSS_PREPROCESSOR_EXT = /(\.scss|\.less|\.styl)$/;
+const CSS_PREPROCESSOR_EXT = /(\.scss|\.sass|\.less|\.styl)$/;
 
 let wrapHostForTest: ((host: ts.CompilerHost) => ts.CompilerHost)|null = null;