diff --git a/sdk/bin/dart2js_sdk.bat b/sdk/bin/dart2js_sdk.bat
index acc4e17bd7e..8485cdc7dfb 100755
--- a/sdk/bin/dart2js_sdk.bat
+++ b/sdk/bin/dart2js_sdk.bat
@@ -28,7 +28,7 @@ if _%DART2JS_DEVELOPER_MODE%_ == _1_ (
 )
 
 if exist "%SNAPSHOT%" (
-  set EXTRA_OPTIONS=%EXTRA_OPTIONS% "--library-root=%SDK_DIR%"
+  set EXTRA_OPTIONS=%EXTRA_OPTIONS% "--libraries-spec=%SDK_DIR%\lib\libraries.json"
 )
 
 rem We allow extra vm options to be passed in through an environment variable.