diff --git a/src/vs/workbench/api/browser/mainThreadEditorTabs.ts b/src/vs/workbench/api/browser/mainThreadEditorTabs.ts
index c4e1424ba8f..d3095a8ab90 100644
--- a/src/vs/workbench/api/browser/mainThreadEditorTabs.ts
+++ b/src/vs/workbench/api/browser/mainThreadEditorTabs.ts
@@ -55,7 +55,8 @@ export class MainThreadEditorTabs {
 			resource: editor instanceof SideBySideEditorInput ? EditorResourceAccessor.getCanonicalUri(editor, { supportSideBySide: SideBySideEditor.PRIMARY }) : EditorResourceAccessor.getCanonicalUri(editor),
 			editorId,
 			additionalResourcesAndViewIds: [],
-			isActive: group.isActive(editor)
+			isActive: group.isActive(editor),
+			isDirty: editor.isDirty()
 		};
 		tab.additionalResourcesAndViewIds.push({ resource: tab.resource, viewId: tab.editorId });
 		if (editor instanceof SideBySideEditorInput) {
@@ -173,6 +174,14 @@ export class MainThreadEditorTabs {
 		this._groupModel.get(groupId)!.activeTab = activeTab;
 	}
 
+	private _onDidTabDirty(groupId: number, editorIndex: number, editor: EditorInput) {
+		const tab = this._groupModel.get(groupId)?.tabs[editorIndex];
+		if (!tab) {
+			return;
+		}
+		tab.isDirty = editor.isDirty();
+	}
+
 	/**
 	 * Builds the model from scratch based on the current state of the editor service.
 	 */
@@ -254,6 +263,11 @@ export class MainThreadEditorTabs {
 					this._onDidTabActiveChange(event.groupId, event.editorIndex);
 					break;
 				}
+			case GroupModelChangeKind.EDITOR_DIRTY:
+				if (event.editorIndex && event.editor) {
+					this._onDidTabDirty(event.groupId, event.editorIndex, event.editor);
+					break;
+				}
 			default:
 				// If it's not an optimized case we rebuild the tabs model from scratch
 				this._createTabsModel();
diff --git a/src/vs/workbench/api/common/extHost.protocol.ts b/src/vs/workbench/api/common/extHost.protocol.ts
index c448595d763..ea632c99395 100644
--- a/src/vs/workbench/api/common/extHost.protocol.ts
+++ b/src/vs/workbench/api/common/extHost.protocol.ts
@@ -631,6 +631,7 @@ export interface IEditorTabDto {
 	resource?: UriComponents;
 	editorId?: string;
 	isActive: boolean;
+	isDirty: boolean;
 	additionalResourcesAndViewIds: { resource?: UriComponents; viewId?: string }[];
 }
 
diff --git a/src/vs/workbench/api/common/extHostEditorTabs.ts b/src/vs/workbench/api/common/extHostEditorTabs.ts
index 002d80510b8..1f780100c5e 100644
--- a/src/vs/workbench/api/common/extHostEditorTabs.ts
+++ b/src/vs/workbench/api/common/extHostEditorTabs.ts
@@ -17,6 +17,7 @@ export interface IEditorTab {
 	resource: vscode.Uri | undefined;
 	viewId: string | undefined;
 	isActive: boolean;
+	isDirty: boolean;
 	additionalResourcesAndViewIds: { resource: vscode.Uri | undefined; viewId: string | undefined }[];
 	move(index: number, viewColumn: ViewColumn): Promise<void>;
 	close(): Promise<void>;
@@ -91,6 +92,7 @@ export class ExtHostEditorTabs implements IExtHostEditorTabs {
 			additionalResourcesAndViewIds: tabDto.additionalResourcesAndViewIds.map(({ resource, viewId }) => ({ resource: URI.revive(resource), viewId })),
 			viewId: tabDto.editorId,
 			isActive: tabDto.isActive,
+			isDirty: tabDto.isDirty,
 			move: async (index: number, viewColumn: ViewColumn) => {
 				this._proxy.$moveTab(tabDto, index, typeConverters.ViewColumn.from(viewColumn));
 				// TODO: Need an on did change tab event at the group level
diff --git a/src/vscode-dts/vscode.proposed.tabs.d.ts b/src/vscode-dts/vscode.proposed.tabs.d.ts
index 619d0184442..09fb65e6d7d 100644
--- a/src/vscode-dts/vscode.proposed.tabs.d.ts
+++ b/src/vscode-dts/vscode.proposed.tabs.d.ts
@@ -50,6 +50,11 @@ declare module 'vscode' {
 		 */
 		readonly isActive: boolean;
 
+		/**
+		 * Whether or not the dirty indicator is present on the tab
+		 */
+		readonly isDirty: boolean;
+
 		/**
 		 * Moves a tab to the given index within the column.
 		 * If the index is out of range, the tab will be moved to the end of the column.
@@ -77,7 +82,7 @@ declare module 'vscode' {
 		/**
 		 * All the groups within the group container
 		 */
-		all: TabGroup[];
+		readonly all: TabGroup[];
 
 		/**
 		 * An {@link Event} which fires when a group changes.
@@ -90,21 +95,21 @@ declare module 'vscode' {
 		/**
 		 * Whether or not the group is currently active
 		 */
-		isActive: boolean;
+		readonly isActive: boolean;
 
 		/**
 		 * The view column of the groups
 		 */
-		viewColumn: ViewColumn;
+		readonly viewColumn: ViewColumn;
 
 		/**
 		 * The active tab within the group
 		 */
-		activeTab: Tab | undefined;
+		readonly activeTab: Tab | undefined;
 
 		/**
 		 * The list of tabs contained within the group
 		 */
-		tabs: Tab[];
+		readonly tabs: Tab[];
 	}
 }