diff --git a/quartz.layout.ts b/quartz.layout.ts
index c7cb463..59f9a28 100644
--- a/quartz.layout.ts
+++ b/quartz.layout.ts
@@ -41,7 +41,7 @@ export const defaultContentPageLayout: PageLayout = {
     Component.Explorer({
 	    filterFn: (node) => {
 		    const omit = new Set(["extra", "note", "template", "volume"])
-		    return !omit.has(node.name.toLowerCase())
+		    return !omit.has((node.name || "").toLowerCase())
 	    },
     }),
   ],
@@ -70,7 +70,7 @@ export const defaultListPageLayout: PageLayout = {
     Component.Explorer({
 	    filterFn: (node) => {
 		    const omit = new Set(["extra", "note", "template", "volume"])
-		    return !omit.has(node.name.toLowerCase())
+		    return !omit.has((node.name || "").toLowerCase())
 	    },
     }),
   ],