diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6864a4b..a8903ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Version 3.1.1 - (Unreleased)
 
 - Strip unnecessary whitespace from `Stanza` elements
+- Allow `Builder` instances to be passed into the `cnode` function
 - Bugfix. Handle `null` and `undefined` values inside `stx` tagged template literals.
 
 ## Version 3.1.0 - (2024-12-16)
diff --git a/src/builder.js b/src/builder.js
index 3a1bc35..e8e9aab 100644
--- a/src/builder.js
+++ b/src/builder.js
@@ -293,10 +293,13 @@ class Builder {
      * name and an attributes object to create the child it uses an
      * existing DOM element object.
      *
-     * @param {Element} elem - A DOM element.
+     * @param {Element|Builder} elem - A DOM element.
      * @return {Builder} The Strophe.Builder object.
      */
     cnode(elem) {
+        if (elem instanceof Builder) {
+            elem = elem.tree();
+        }
         let impNode;
         const xmlGen = xmlGenerator();
         try {
diff --git a/src/types/builder.d.ts b/src/types/builder.d.ts
index a848ec8..2248531 100644
--- a/src/types/builder.d.ts
+++ b/src/types/builder.d.ts
@@ -169,10 +169,10 @@ declare class Builder {
      * name and an attributes object to create the child it uses an
      * existing DOM element object.
      *
-     * @param {Element} elem - A DOM element.
+     * @param {Element|Builder} elem - A DOM element.
      * @return {Builder} The Strophe.Builder object.
      */
-    cnode(elem: Element): Builder;
+    cnode(elem: Element | Builder): Builder;
     /**
      * Add a child text element.
      *