diff --git a/src/compiler/interfaces.ts b/src/compiler/interfaces.ts
index a9920750f9..248175da59 100644
--- a/src/compiler/interfaces.ts
+++ b/src/compiler/interfaces.ts
@@ -131,9 +131,9 @@ export interface Style extends BaseNode {
 
 export interface Ast {
 	html: TemplateNode;
-	css: Style;
-	instance: Script;
-	module: Script;
+	css?: Style;
+	instance?: Script;
+	module?: Script;
 }
 
 export interface Warning {