diff --git a/index.js b/index.js
index 2639fd3..5498d09 100644
--- a/index.js
+++ b/index.js
@@ -14,25 +14,20 @@ function slug() {
 function transformer(ast) {
   slugs.reset();
 
-  visit(ast, 'heading', function (node) {
+  visit(ast, 'heading', visitor);
+
+  function visitor(node) {
     var id = slugs.slug(toString(node));
-    var data = patch(node, 'data', {});
-
-    /* Non-html */
-    patch(data, 'id', id);
-    /* Legacy remark-html */
-    patch(data, 'htmlAttributes', {});
-    /* Current remark-html */
-    patch(data, 'hProperties', {});
-    patch(data.htmlAttributes, 'id', id);
-    patch(data.hProperties, 'id', id);
-  });
-}
 
-function patch(context, key, value) {
-  if (!context[key]) {
-    context[key] = value;
-  }
+    if (!node.data) {
+      node.data = {};
+    }
 
-  return context[key];
+    if (!node.data.hProperties) {
+      node.data.hProperties = {};
+    }
+
+    node.data.id = id;
+    node.data.hProperties.id = id;
+  }
 }
diff --git a/test.js b/test.js
index f7e8a8d..9e2ba0e 100644
--- a/test.js
+++ b/test.js
@@ -145,10 +145,6 @@ test('slugs', function (t) {
 function heading(label, id) {
   return u('heading', {
     depth: 2,
-    data: {
-      id: id,
-      htmlAttributes: {id: id},
-      hProperties: {id: id}
-    }
+    data: {id: id, hProperties: {id: id}}
   }, label ? [u('text', label)] : []);
 }