diff --git a/src/tsconfig.strictNullChecks.json b/src/tsconfig.strictNullChecks.json
index 3c0eff3056e12b4fa4c2dccfbed1d28165046fed..a9c95b17047be5bbd306970462dc74da9ec18e06 100644
--- a/src/tsconfig.strictNullChecks.json
+++ b/src/tsconfig.strictNullChecks.json
@@ -527,6 +527,7 @@
 		"./vs/workbench/browser/parts/editor/baseEditor.ts",
 		"./vs/workbench/browser/parts/editor/binaryEditor.ts",
 		"./vs/workbench/browser/parts/editor/editor.ts",
+		"./vs/workbench/browser/parts/editor/editorControl.ts",
 		"./vs/workbench/browser/parts/editor/editorWidgets.ts",
 		"./vs/workbench/browser/parts/editor/rangeDecorations.ts",
 		"./vs/workbench/browser/parts/editor/resourceViewer.ts",
diff --git a/src/vs/workbench/browser/parts/editor/baseEditor.ts b/src/vs/workbench/browser/parts/editor/baseEditor.ts
index 5dff202482566f72ac007f3ab5d49ce6a107fdbf..0e3ad345309b7fb9061bb301dd307b7617a8ed5d 100644
--- a/src/vs/workbench/browser/parts/editor/baseEditor.ts
+++ b/src/vs/workbench/browser/parts/editor/baseEditor.ts
@@ -77,7 +77,7 @@ export abstract class BaseEditor extends Panel implements IEditor {
 	 * The provided cancellation token should be used to test if the operation
 	 * was cancelled.
 	 */
-	setInput(input: EditorInput, options: EditorOptions, token: CancellationToken): Promise<void> {
+	setInput(input: EditorInput, options: EditorOptions | null, token: CancellationToken): Promise<void> {
 		this._input = input;
 		this._options = options;
 
@@ -100,7 +100,7 @@ export abstract class BaseEditor extends Panel implements IEditor {
 	 * Sets the given options to the editor. Clients should apply the options
 	 * to the current input.
 	 */
-	setOptions(options: EditorOptions): void {
+	setOptions(options: EditorOptions | null): void {
 		this._options = options;
 	}
 
diff --git a/src/vs/workbench/browser/parts/editor/editorControl.ts b/src/vs/workbench/browser/parts/editor/editorControl.ts
index a557a7d82c469c900896d85722653eb7f0d85dc4..0d6945988f4282d456e475e4b086ee4567562197 100644
--- a/src/vs/workbench/browser/parts/editor/editorControl.ts
+++ b/src/vs/workbench/browser/parts/editor/editorControl.ts
@@ -30,10 +30,10 @@ export class EditorControl extends Disposable {
 	private _onDidFocus: Emitter<void> = this._register(new Emitter<void>());
 	get onDidFocus(): Event<void> { return this._onDidFocus.event; }
 
-	private _onDidSizeConstraintsChange = this._register(new Emitter<{ width: number; height: number; }>());
-	get onDidSizeConstraintsChange(): Event<{ width: number; height: number; }> { return this._onDidSizeConstraintsChange.event; }
+	private _onDidSizeConstraintsChange = this._register(new Emitter<{ width: number; height: number; } | undefined>());
+	get onDidSizeConstraintsChange(): Event<{ width: number; height: number; } | undefined> { return this._onDidSizeConstraintsChange.event; }
 
-	private _activeControl: BaseEditor;
+	private _activeControl: BaseEditor | null;
 	private controls: BaseEditor[] = [];
 
 	private activeControlDisposeables: IDisposable[] = [];
@@ -52,7 +52,7 @@ export class EditorControl extends Disposable {
 		this.editorOperation = this._register(new LongRunningOperation(progressService));
 	}
 
-	get activeControl(): BaseEditor {
+	get activeControl() {
 		return this._activeControl;
 	}
 
@@ -60,10 +60,13 @@ export class EditorControl extends Disposable {
 
 		// Editor control
 		const descriptor = Registry.as<IEditorRegistry>(EditorExtensions.Editors).getEditor(editor);
+		if (!descriptor) {
+			throw new Error('No editor descriptor found');
+		}
 		const control = this.doShowEditorControl(descriptor);
 
 		// Set input
-		return this.doSetInput(control, editor, options).then((editorChanged => (({ control, editorChanged } as IOpenEditorResult))));
+		return this.doSetInput(control, editor, options || null).then((editorChanged => (({ control, editorChanged } as IOpenEditorResult))));
 	}
 
 	private doShowEditorControl(descriptor: IEditorDescriptor): BaseEditor {
@@ -129,7 +132,7 @@ export class EditorControl extends Disposable {
 		return control;
 	}
 
-	private doSetActiveControl(control: BaseEditor) {
+	private doSetActiveControl(control: BaseEditor | null) {
 		this._activeControl = control;
 
 		// Clear out previous active control listeners
@@ -145,7 +148,7 @@ export class EditorControl extends Disposable {
 		this._onDidSizeConstraintsChange.fire(undefined);
 	}
 
-	private doSetInput(control: BaseEditor, editor: EditorInput, options: EditorOptions): Promise<boolean> {
+	private doSetInput(control: BaseEditor, editor: EditorInput, options: EditorOptions | null): Promise<boolean> {
 
 		// If the input did not change, return early and only apply the options
 		// unless the options instruct us to force open it even if it is the same