diff --git a/extensions/ipynb/src/ipynbMain.ts b/extensions/ipynb/src/ipynbMain.ts
index 72c949d736c..5ac60c568e5 100644
--- a/extensions/ipynb/src/ipynbMain.ts
+++ b/extensions/ipynb/src/ipynbMain.ts
@@ -41,25 +41,6 @@ export function activate(context: vscode.ExtensionContext) {
 		exportNotebook: (notebook: vscode.NotebookData): string => {
 			return exportNotebook(notebook, serializer);
 		},
-		setKernelSpec: async (resource: vscode.Uri, kernelspec: unknown): Promise<boolean> => {
-			const document = vscode.workspace.notebookDocuments.find(doc => doc.uri.toString() === resource.toString());
-			if (!document) {
-				return false;
-			}
-
-			const edit = new vscode.WorkspaceEdit();
-			edit.replaceNotebookMetadata(resource, {
-				...document.metadata,
-				custom: {
-					...(document.metadata.custom ?? {}),
-					metadata: {
-						...(document.metadata.custom?.metadata ?? {}),
-						kernelspec: kernelspec
-					},
-				}
-			});
-			return vscode.workspace.applyEdit(edit);
-		},
 		setNotebookMetadata: async (resource: vscode.Uri, metadata: Partial<NotebookMetadata>): Promise<boolean> => {
 			const document = vscode.workspace.notebookDocuments.find(doc => doc.uri.toString() === resource.toString());
 			if (!document) {