diff --git a/extensions/ipynb/src/notebookSerializer.ts b/extensions/ipynb/src/notebookSerializer.ts
index a9331529728..7d5cef2b3d3 100644
--- a/extensions/ipynb/src/notebookSerializer.ts
+++ b/extensions/ipynb/src/notebookSerializer.ts
@@ -22,7 +22,7 @@ export class NotebookSerializer implements vscode.NotebookSerializer {
 		} catch {
 		}
 
-		let json = contents ? (JSON.parse(contents) as Partial<nbformat.INotebookContent>) : {};
+		let json = contents && /\S/.test(contents) ? (JSON.parse(contents) as Partial<nbformat.INotebookContent>) : {};
 
 		if (json.__webview_backup) {
 			const backupId = json.__webview_backup;