diff --git a/packages/runtime-vapor/src/apiCreateFor.ts b/packages/runtime-vapor/src/apiCreateFor.ts
index 6c5e86ab3..6b9482ffe 100644
--- a/packages/runtime-vapor/src/apiCreateFor.ts
+++ b/packages/runtime-vapor/src/apiCreateFor.ts
@@ -233,7 +233,7 @@ export const createFor = (
         if (endOffset !== 0) {
           anchorFallback = normalizeAnchor(
             newBlocks[newLength - endOffset].nodes,
-          )
+          )!
         }
 
         while (startOffset < sharedBlockCount - endOffset) {