diff --git a/src/core/render/compiler.js b/src/core/render/compiler.js
index 74d9ed382..6ea1fda4c 100644
--- a/src/core/render/compiler.js
+++ b/src/core/render/compiler.js
@@ -71,6 +71,7 @@ export class Compiler {
     this.router = router
     this.cacheTree = {}
     this.toc = []
+    this.cacheTOC = {}
     this.linkTarget = config.externalLinkTarget || '_blank'
     this.contentBase = router.getBasePath()