diff --git a/src/tsconfig.strictNullChecks.json b/src/tsconfig.strictNullChecks.json
index 430f6f403a4..8c83108d46e 100644
--- a/src/tsconfig.strictNullChecks.json
+++ b/src/tsconfig.strictNullChecks.json
@@ -615,6 +615,8 @@
 		"./vs/workbench/parts/scm/electron-browser/scmMenus.ts",
 		"./vs/workbench/parts/scm/electron-browser/scmUtil.ts",
 		"./vs/workbench/parts/search/browser/patternInputWidget.ts",
+		"./vs/workbench/parts/search/browser/replaceContributions.ts",
+		"./vs/workbench/parts/search/browser/replaceService.ts",
 		"./vs/workbench/parts/search/common/constants.ts",
 		"./vs/workbench/parts/search/common/queryBuilder.ts",
 		"./vs/workbench/parts/search/common/replace.ts",
@@ -758,6 +760,7 @@
 		"./vs/workbench/services/keybinding/test/keybindingIO.test.ts",
 		"./vs/workbench/services/keybinding/test/keyboardMapperTestUtils.ts",
 		"./vs/workbench/services/keybinding/test/macLinuxFallbackKeyboardMapper.test.ts",
+		"./vs/workbench/services/keybinding/test/macLinuxKeyboardMapper.test.ts",
 		"./vs/workbench/services/keybinding/test/windowsKeyboardMapper.test.ts",
 		"./vs/workbench/services/mode/common/workbenchModeService.ts",
 		"./vs/workbench/services/notification/common/notificationService.ts",
@@ -809,7 +812,6 @@
 		"./vs/workbench/services/title/common/titleService.ts",
 		"./vs/workbench/services/workspace/common/workspaceEditing.ts",
 		"./vs/workbench/test/common/editor/editorOptions.test.ts",
-		"./vs/workbench/services/keybinding/test/macLinuxKeyboardMapper.test.ts",
 		"./vs/workbench/test/common/notifications.test.ts",
 		"./vs/workbench/test/electron-browser/api/extHostTypes.test.ts",
 		"./vs/workbench/test/electron-browser/api/mock.ts"
diff --git a/src/vs/editor/common/services/resolverService.ts b/src/vs/editor/common/services/resolverService.ts
index 28aca391a32..7cc218bec57 100644
--- a/src/vs/editor/common/services/resolverService.ts
+++ b/src/vs/editor/common/services/resolverService.ts
@@ -36,7 +36,7 @@ export interface ITextModelContentProvider {
 	/**
 	 * Given a resource, return the content of the resource as `ITextModel`.
 	 */
-	provideTextContent(resource: URI): Promise<ITextModel>;
+	provideTextContent(resource: URI): Promise<ITextModel> | null;
 }
 
 export interface ITextEditorModel extends IEditorModel {
diff --git a/src/vs/workbench/parts/search/browser/replaceService.ts b/src/vs/workbench/parts/search/browser/replaceService.ts
index 2a4207002c6..79b23bf636d 100644
--- a/src/vs/workbench/parts/search/browser/replaceService.ts
+++ b/src/vs/workbench/parts/search/browser/replaceService.ts
@@ -46,7 +46,7 @@ export class ReplacePreviewContentProvider implements ITextModelContentProvider,
 		this.textModelResolverService.registerTextModelContentProvider(network.Schemas.internal, this);
 	}
 
-	provideTextContent(uri: URI): Promise<ITextModel> {
+	provideTextContent(uri: URI): Promise<ITextModel> | null {
 		if (uri.fragment === REPLACE_PREVIEW) {
 			return this.instantiationService.createInstance(ReplacePreviewModel).resolve(uri);
 		}
@@ -103,7 +103,7 @@ export class ReplaceService implements IReplaceService {
 	replace(match: Match): Promise<any>;
 	replace(files: FileMatch[], progress?: IProgressRunner): Promise<any>;
 	replace(match: FileMatchOrMatch, progress?: IProgressRunner, resource?: URI): Promise<any>;
-	replace(arg: any, progress: IProgressRunner | null = null, resource: URI | null = null): Promise<any> {
+	replace(arg: any, progress: IProgressRunner | undefined = undefined, resource: URI | null = null): Promise<any> {
 
 		const edits: ResourceTextEdit[] = this.createEdits(arg, resource);
 		return this.bulkEditorService.apply({ edits }, { progress }).then(() => this.textFileService.saveAll(edits.map(e => e.resource)));