diff --git a/src/vs/workbench/browser/parts/editor/tabsTitleControl.ts b/src/vs/workbench/browser/parts/editor/tabsTitleControl.ts
index e1f6ef8a1b2..7958e1f6d11 100644
--- a/src/vs/workbench/browser/parts/editor/tabsTitleControl.ts
+++ b/src/vs/workbench/browser/parts/editor/tabsTitleControl.ts
@@ -204,7 +204,7 @@ export class TabsTitleControl extends TitleControl {
 		editorsOfGroup.forEach((editor, index) => {
 			const tabContainer = this.tabsContainer.children[index];
 			if (tabContainer instanceof HTMLElement) {
-				const isPinned = group.isPinned(editor);
+				const isPinned = group.isPinned(index);
 				const isActive = group.isActive(editor);
 				const isDirty = editor.isDirty();
 
diff --git a/src/vs/workbench/common/editor.ts b/src/vs/workbench/common/editor.ts
index 0b1e4790150..00a6051677b 100644
--- a/src/vs/workbench/common/editor.ts
+++ b/src/vs/workbench/common/editor.ts
@@ -917,6 +917,7 @@ export interface IEditorGroup {
 	getEditors(mru?: boolean): IEditorInput[];
 	isActive(editor: IEditorInput): boolean;
 	isPreview(editor: IEditorInput): boolean;
+	isPinned(index: number): boolean;
 	isPinned(editor: IEditorInput): boolean;
 }
 
diff --git a/src/vs/workbench/common/editor/editorStacksModel.ts b/src/vs/workbench/common/editor/editorStacksModel.ts
index 0c761a5822a..1e136c9ef89 100644
--- a/src/vs/workbench/common/editor/editorStacksModel.ts
+++ b/src/vs/workbench/common/editor/editorStacksModel.ts
@@ -482,9 +482,20 @@ export class EditorGroup implements IEditorGroup {
 		this.closeEditor(oldPreview);
 	}
 
-	public isPinned(editor: EditorInput): boolean {
-		const index = this.indexOf(editor);
-		if (index === -1) {
+	public isPinned(editor: EditorInput): boolean;
+	public isPinned(index: number): boolean;
+	public isPinned(arg1: EditorInput | number): boolean {
+		let editor: EditorInput;
+		let index: number;
+		if (typeof arg1 === 'number') {
+			editor = this.editors[arg1];
+			index = arg1;
+		} else {
+			editor = arg1;
+			index = this.indexOf(editor);
+		}
+
+		if (index === -1 || !editor) {
 			return false; // editor not found
 		}
 
diff --git a/src/vs/workbench/test/browser/editorStacksModel.test.ts b/src/vs/workbench/test/browser/editorStacksModel.test.ts
index eea5e6d990f..bf0099788ef 100644
--- a/src/vs/workbench/test/browser/editorStacksModel.test.ts
+++ b/src/vs/workbench/test/browser/editorStacksModel.test.ts
@@ -486,6 +486,7 @@ suite('Editor Stacks Model', () => {
 		assert.equal(group.isActive(input1), true);
 		assert.equal(group.isPreview(input1), false);
 		assert.equal(group.isPinned(input1), true);
+		assert.equal(group.isPinned(0), true);
 
 		assert.equal(events.opened[0], input1);
 		assert.equal(events.activated[0], input1);
@@ -508,6 +509,7 @@ suite('Editor Stacks Model', () => {
 		assert.equal(group.isActive(input2), true);
 		assert.equal(group.isPreview(input2), true);
 		assert.equal(group.isPinned(input2), false);
+		assert.equal(group.isPinned(0), false);
 
 		assert.equal(events.opened[1], input2);
 		assert.equal(events.activated[1], input2);
@@ -536,6 +538,7 @@ suite('Editor Stacks Model', () => {
 		assert.equal(group.isActive(input3), true);
 		assert.equal(group.isPreview(input3), false);
 		assert.equal(group.isPinned(input3), true);
+		assert.equal(group.isPinned(0), true);
 
 		assert.equal(events.opened[2], input3);
 		assert.equal(events.activated[2], input3);
@@ -565,6 +568,7 @@ suite('Editor Stacks Model', () => {
 		assert.equal(group.isActive(input4), true);
 		assert.equal(group.isPreview(input4), true);
 		assert.equal(group.isPinned(input4), false);
+		assert.equal(group.isPinned(0), false);
 
 		assert.equal(events.opened[3], input4);
 		assert.equal(events.activated[3], input4);
@@ -692,12 +696,15 @@ suite('Editor Stacks Model', () => {
 		assert.equal(group.activeEditor, input1);
 		assert.equal(group.isActive(input1), true);
 		assert.equal(group.isPinned(input1), true);
+		assert.equal(group.isPinned(0), true);
 		assert.equal(group.isPreview(input1), false);
 		assert.equal(group.isActive(input2), false);
 		assert.equal(group.isPinned(input2), true);
+		assert.equal(group.isPinned(1), true);
 		assert.equal(group.isPreview(input2), false);
 		assert.equal(group.isActive(input3), false);
 		assert.equal(group.isPinned(input3), true);
+		assert.equal(group.isPinned(2), true);
 		assert.equal(group.isPreview(input3), false);
 
 		const mru = group.getEditors(true);