diff --git a/src/mol-script/script.ts b/src/mol-script/script.ts
index ca62dd315c0a9990d782ba1905309adbcd687d45..a1e4e5d321f5daba3efaae390481e5f70b883cb3 100644
--- a/src/mol-script/script.ts
+++ b/src/mol-script/script.ts
@@ -15,9 +15,9 @@ import { assertUnreachable } from '../mol-util/type-helpers';
 
 export { Script };
 
-interface Script { expression: string, language: Script.Language}
+interface Script { expression: string, language: Script.Language }
 
-function Script(expression: string = '(sel.atom.all)', language: Script.Language = 'mol-script'): Script {
+function Script(expression: string, language: Script.Language): Script {
     return { expression, language };
 }