diff --git a/extensions/vscode-api-tests/package.json b/extensions/vscode-api-tests/package.json
index da178fb01ae..dcdd8b608a9 100644
--- a/extensions/vscode-api-tests/package.json
+++ b/extensions/vscode-api-tests/package.json
@@ -119,7 +119,7 @@
     ],
     "notebooks": [
       {
-        "viewType": "notebookCoreTest",
+        "type": "notebookCoreTest",
         "displayName": "Notebook Core Test",
         "selector": [
           {
@@ -129,7 +129,7 @@
         ]
       },
       {
-        "viewType": "notebook.nbdtest",
+        "type": "notebook.nbdtest",
         "displayName": "notebook.nbdtest",
         "selector": [
           {
@@ -138,7 +138,7 @@
         ]
       },
       {
-        "viewType": "notebook.nbdserializer",
+        "type": "notebook.nbdserializer",
         "displayName": "notebook.nbdserializer",
         "selector": [
           {
diff --git a/extensions/vscode-notebook-tests/package.json b/extensions/vscode-notebook-tests/package.json
index 6a0e2d648de..cc0264bb1a3 100644
--- a/extensions/vscode-notebook-tests/package.json
+++ b/extensions/vscode-notebook-tests/package.json
@@ -36,7 +36,7 @@
     ],
     "notebooks": [
       {
-        "viewType": "notebookSmokeTest",
+        "type": "notebookSmokeTest",
         "displayName": "Notebook Smoke Test",
         "selector": [
           {
@@ -60,7 +60,7 @@
       "notebook/cell/title": [
         {
           "command": "vscode-notebook-tests.debugAction",
-          "when": "notebookViewType == notebookSmokeTest",
+          "when": "notebookType == notebookSmokeTest",
           "group": "inline@1"
         }
       ]
diff --git a/src/vs/workbench/contrib/notebook/browser/extensionPoint.ts b/src/vs/workbench/contrib/notebook/browser/extensionPoint.ts
index 9db9e5c5991..3e827183b54 100644
--- a/src/vs/workbench/contrib/notebook/browser/extensionPoint.ts
+++ b/src/vs/workbench/contrib/notebook/browser/extensionPoint.ts
@@ -10,8 +10,6 @@ import { NotebookEditorPriority, NotebookRendererEntrypoint, RendererMessagingSp
 
 namespace NotebookEditorContribution {
 	export const type = 'type';
-	/** @deprecated use type */
-	export const viewType = 'viewType';
 	export const displayName = 'displayName';
 	export const selector = 'selector';
 	export const priority = 'priority';
@@ -19,16 +17,13 @@ namespace NotebookEditorContribution {
 
 export interface INotebookEditorContribution {
 	readonly [NotebookEditorContribution.type]: string;
-	/** @deprecated use type */
-	readonly [NotebookEditorContribution.viewType]: string;
 	readonly [NotebookEditorContribution.displayName]: string;
 	readonly [NotebookEditorContribution.selector]?: readonly { filenamePattern?: string; excludeFileNamePattern?: string; }[];
 	readonly [NotebookEditorContribution.priority]?: string;
 }
 
 namespace NotebookRendererContribution {
-	/** @deprecated use type */
-	export const viewType = 'viewType';
+
 	export const id = 'id';
 	export const displayName = 'displayName';
 	export const mimeTypes = 'mimeTypes';
@@ -40,8 +35,6 @@ namespace NotebookRendererContribution {
 
 export interface INotebookRendererContribution {
 	readonly [NotebookRendererContribution.id]?: string;
-	/** @deprecated use type */
-	readonly [NotebookRendererContribution.viewType]?: string;
 	readonly [NotebookRendererContribution.displayName]: string;
 	readonly [NotebookRendererContribution.mimeTypes]?: readonly string[];
 	readonly [NotebookRendererContribution.entrypoint]: NotebookRendererEntrypoint;
@@ -66,10 +59,6 @@ const notebookProviderContribution: IJSONSchema = {
 				type: 'string',
 				description: nls.localize('contributes.notebook.provider.viewType', 'Type of the notebook.'),
 			},
-			[NotebookEditorContribution.viewType]: {
-				type: 'string',
-				deprecationMessage: nls.localize('viewType.deprecated2', 'Rename `viewType` to `type`.'),
-			},
 			[NotebookEditorContribution.displayName]: {
 				type: 'string',
 				description: nls.localize('contributes.notebook.provider.displayName', 'Human readable name of the notebook.'),
@@ -125,11 +114,6 @@ const notebookRendererContribution: IJSONSchema = {
 				type: 'string',
 				description: nls.localize('contributes.notebook.renderer.viewType', 'Unique identifier of the notebook output renderer.'),
 			},
-			[NotebookRendererContribution.viewType]: {
-				type: 'string',
-				deprecationMessage: nls.localize('contributes.notebook.provider.viewType.deprecated', 'Rename `viewType` to `id`.'),
-				description: nls.localize('contributes.notebook.renderer.viewType', 'Unique identifier of the notebook output renderer.'),
-			},
 			[NotebookRendererContribution.displayName]: {
 				type: 'string',
 				description: nls.localize('contributes.notebook.renderer.displayName', 'Human readable name of the notebook output renderer.'),
diff --git a/src/vs/workbench/contrib/notebook/browser/notebookServiceImpl.ts b/src/vs/workbench/contrib/notebook/browser/notebookServiceImpl.ts
index baa92c9de3c..a85a27938d0 100644
--- a/src/vs/workbench/contrib/notebook/browser/notebookServiceImpl.ts
+++ b/src/vs/workbench/contrib/notebook/browser/notebookServiceImpl.ts
@@ -94,9 +94,20 @@ export class NotebookProviderInfoStore extends Disposable {
 
 		for (const extension of extensions) {
 			for (const notebookContribution of extension.value) {
+
+				if (!notebookContribution.type) {
+					extension.collector.error(`Notebook does not specify type-property`);
+					continue;
+				}
+
+				if (this.get(notebookContribution.type)) {
+					extension.collector.error(`Notebook type '${notebookContribution.type}' already used`);
+					continue;
+				}
+
 				this.add(new NotebookProviderInfo({
 					extension: extension.description.identifier,
-					id: notebookContribution.type || notebookContribution.viewType,
+					id: notebookContribution.type,
 					displayName: notebookContribution.displayName,
 					selectors: notebookContribution.selector || [],
 					priority: this._convertPriority(notebookContribution.priority),
@@ -353,7 +364,7 @@ export class NotebookService extends Disposable implements INotebookService {
 						continue;
 					}
 
-					const id = notebookContribution.id ?? notebookContribution.viewType;
+					const id = notebookContribution.id;
 					if (!id) {
 						extension.collector.error(`Notebook renderer does not specify id-property`);
 						continue;