diff --git a/iscroll/iscroll-4.2.d.ts b/iscroll/iscroll-4.2.d.ts
index 938da44ac..aee179cac 100644
--- a/iscroll/iscroll-4.2.d.ts
+++ b/iscroll/iscroll-4.2.d.ts
@@ -39,7 +39,7 @@ interface iScrollOptions {
     wheelAction?: string;
 
     // Snap
-    snap?: bool;
+    snap?: any;
     snapThreshold?: number;
 
     // Events