diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index 5a08e8f9662..0f70d961575 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -1480,8 +1480,10 @@ declare module 'vscode' {
 
 		// UI properties (get/set)
 		label: string;
-		supportedLanguages: string[];
 		description?: string;
+		isPreferred?: boolean;
+
+		supportedLanguages: string[];
 		hasExecutionOrder?: boolean;
 		preloads?: NotebookKernelPreload[];
 
diff --git a/src/vs/workbench/api/common/extHostNotebookKernels.ts b/src/vs/workbench/api/common/extHostNotebookKernels.ts
index d6ed8d59ece..6f1b2935be8 100644
--- a/src/vs/workbench/api/common/extHostNotebookKernels.ts
+++ b/src/vs/workbench/api/common/extHostNotebookKernels.ts
@@ -91,6 +91,13 @@ export class ExtHostNotebookKernels implements ExtHostNotebookKernelsShape {
 				data.description = value;
 				_update();
 			},
+			get isPreferred() {
+				return data.isPreferred ?? false;
+			},
+			set isPreferred(value) {
+				data.isPreferred = value;
+				_update();
+			},
 			get supportedLanguages() {
 				return data.supportedLanguages;
 			},