diff --git a/src/generators/legacy-html/generate.mjs b/src/generators/legacy-html/generate.mjs
index 4126c13c..fe39aec6 100644
--- a/src/generators/legacy-html/generate.mjs
+++ b/src/generators/legacy-html/generate.mjs
@@ -44,7 +44,7 @@ export async function processChunk(slicedInput, itemIndices, navigation) {
     const toc = String(
       remarkRehypeProcessor.processSync(
         tableOfContents(nodes, {
-          maxDepth: 4,
+          maxDepth: 5,
           parser: tableOfContents.parseToCNode,
         })
       )