diff --git a/src/tsconfig.strictNullChecks.json b/src/tsconfig.strictNullChecks.json
index 87a7602d67a..ba90ef44064 100644
--- a/src/tsconfig.strictNullChecks.json
+++ b/src/tsconfig.strictNullChecks.json
@@ -329,6 +329,7 @@
 		"./vs/editor/contrib/hover/hoverOperation.ts",
 		"./vs/editor/contrib/hover/hoverWidgets.ts",
 		"./vs/editor/contrib/hover/modesGlyphHover.ts",
+		"./vs/editor/contrib/inPlaceReplace/inPlaceReplace.ts",
 		"./vs/editor/contrib/inPlaceReplace/inPlaceReplaceCommand.ts",
 		"./vs/editor/contrib/indentation/indentation.ts",
 		"./vs/editor/contrib/indentation/indentUtils.ts",
diff --git a/src/vs/editor/contrib/inPlaceReplace/inPlaceReplace.ts b/src/vs/editor/contrib/inPlaceReplace/inPlaceReplace.ts
index 1ef5a49d498..d00d578cb2c 100644
--- a/src/vs/editor/contrib/inPlaceReplace/inPlaceReplace.ts
+++ b/src/vs/editor/contrib/inPlaceReplace/inPlaceReplace.ts
@@ -37,7 +37,7 @@ class InPlaceReplaceController implements IEditorContribution {
 	private readonly editor: ICodeEditor;
 	private readonly editorWorkerService: IEditorWorkerService;
 	private decorationIds: string[] = [];
-	private currentRequest: CancelablePromise<IInplaceReplaceSupportResult>;
+	private currentRequest: CancelablePromise<IInplaceReplaceSupportResult | null>;
 	private decorationRemover: CancelablePromise<void>;
 
 	constructor(
@@ -63,21 +63,29 @@ class InPlaceReplaceController implements IEditorContribution {
 		}
 
 		let selection = this.editor.getSelection();
+		if (selection === null) {
+			return Promise.resolve(void 0);
+		}
+
 		const model = this.editor.getModel();
+		if (!model) {
+			return Promise.resolve(void 0);
+		}
+
 		const modelURI = model.uri;
 
 		if (selection.startLineNumber !== selection.endLineNumber) {
 			// Can't accept multiline selection
-			return null;
+			return Promise.resolve(void 0);
 		}
 
 		const state = new EditorState(this.editor, CodeEditorStateFlag.Value | CodeEditorStateFlag.Position);
 
 		if (!this.editorWorkerService.canNavigateValueSet(modelURI)) {
-			return undefined;
+			return Promise.resolve(void 0);
 		}
 
-		this.currentRequest = createCancelablePromise(token => this.editorWorkerService.navigateValueSet(modelURI, selection, up));
+		this.currentRequest = createCancelablePromise(token => this.editorWorkerService.navigateValueSet(modelURI, selection!, up));
 
 		return this.currentRequest.then(result => {
 
@@ -94,7 +102,7 @@ class InPlaceReplaceController implements IEditorContribution {
 			// Selection
 			let editRange = Range.lift(result.range);
 			let highlightRange = result.range;
-			let diff = result.value.length - (selection.endColumn - selection.startColumn);
+			let diff = result.value.length - (selection!.endColumn - selection!.startColumn);
 
 			// highlight
 			highlightRange = {
@@ -104,11 +112,11 @@ class InPlaceReplaceController implements IEditorContribution {
 				endColumn: highlightRange.startColumn + result.value.length
 			};
 			if (diff > 1) {
-				selection = new Selection(selection.startLineNumber, selection.startColumn, selection.endLineNumber, selection.endColumn + diff - 1);
+				selection = new Selection(selection!.startLineNumber, selection!.startColumn, selection!.endLineNumber, selection!.endColumn + diff - 1);
 			}
 
 			// Insert new text
-			const command = new InPlaceReplaceCommand(editRange, selection, result.value);
+			const command = new InPlaceReplaceCommand(editRange, selection!, result.value);
 
 			this.editor.pushUndoStop();
 			this.editor.executeCommand(source, command);
@@ -150,7 +158,7 @@ class InPlaceReplaceUp extends EditorAction {
 	public run(accessor: ServicesAccessor, editor: ICodeEditor): Promise<void> {
 		let controller = InPlaceReplaceController.get(editor);
 		if (!controller) {
-			return undefined;
+			return Promise.resolve(void 0);
 		}
 		return controller.run(this.id, true);
 	}
@@ -175,7 +183,7 @@ class InPlaceReplaceDown extends EditorAction {
 	public run(accessor: ServicesAccessor, editor: ICodeEditor): Promise<void> {
 		let controller = InPlaceReplaceController.get(editor);
 		if (!controller) {
-			return undefined;
+			return Promise.resolve(void 0);
 		}
 		return controller.run(this.id, false);
 	}