diff --git a/lib/rules_block/lheading.mjs b/lib/rules_block/lheading.mjs
index ccdc652..2726285 100644
--- a/lib/rules_block/lheading.mjs
+++ b/lib/rules_block/lheading.mjs
@@ -59,6 +59,7 @@ export default function lheading (state, startLine, endLine/*, silent */) {
 
   if (!level) {
     // Didn't find valid underline
+    state.parentType = oldParentType
     return false
   }