diff --git a/src/types/YXmlElement.js b/src/types/YXmlElement.js
index 76c21298..e9b419b8 100644
--- a/src/types/YXmlElement.js
+++ b/src/types/YXmlElement.js
@@ -24,7 +24,7 @@ import * as decoding from 'lib0/decoding.js'
 export class YXmlElement extends YXmlFragment {
   constructor (nodeName = 'UNDEFINED') {
     super()
-    this.nodeName = nodeName.toUpperCase()
+    this.nodeName = nodeName
     /**
      * @type {Map<string, any>|null}
      * @private
diff --git a/src/types/YXmlFragment.js b/src/types/YXmlFragment.js
index a66282cd..d752e684 100644
--- a/src/types/YXmlFragment.js
+++ b/src/types/YXmlFragment.js
@@ -169,7 +169,7 @@ export class YXmlFragment extends AbstractType {
   querySelector (query) {
     query = query.toUpperCase()
     // @ts-ignore
-    const iterator = new YXmlTreeWalker(this, element => element.nodeName === query)
+    const iterator = new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query)
     const next = iterator.next()
     if (next.done) {
       return null
@@ -192,7 +192,7 @@ export class YXmlFragment extends AbstractType {
   querySelectorAll (query) {
     query = query.toUpperCase()
     // @ts-ignore
-    return Array.from(new YXmlTreeWalker(this, element => element.nodeName === query))
+    return Array.from(new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query))
   }
 
   /**