diff --git a/.changeset/dull-kiwis-agree.md b/.changeset/dull-kiwis-agree.md
new file mode 100644
index 0000000000..9bb85d0daa
--- /dev/null
+++ b/.changeset/dull-kiwis-agree.md
@@ -0,0 +1,6 @@
+---
+"@redocly/openapi-core": patch
+"@redocly/cli": patch
+---
+
+Fixed an issue with the `remove-x-internal` decorator where bundling API descirptions containing discriminators could fail when using **Node.js** v17 or earlier.
diff --git a/packages/core/src/decorators/common/remove-x-internal.ts b/packages/core/src/decorators/common/remove-x-internal.ts
index 06d72d09a9..8b34dc01e4 100644
--- a/packages/core/src/decorators/common/remove-x-internal.ts
+++ b/packages/core/src/decorators/common/remove-x-internal.ts
@@ -65,7 +65,7 @@ export const RemoveXInternal: Oas3Decorator | Oas2Decorator = ({
   return {
     DiscriminatorMapping: {
       enter: (mapping: Record<string, string>) => {
-        originalMapping = structuredClone(mapping);
+        originalMapping = JSON.parse(JSON.stringify(mapping));
       },
     },
     any: {