diff --git a/src/vs/editor/common/modes.ts b/src/vs/editor/common/modes.ts
index a280adb512bee8752e9a95c2a51684698a5101d4..7b614c147cd1b1a64dd8385e99e70b88b3570055 100644
--- a/src/vs/editor/common/modes.ts
+++ b/src/vs/editor/common/modes.ts
@@ -236,7 +236,7 @@ export interface ISuggestResult {
  */
 export interface ISuggestSupport {
 
-	triggerCharacters: string[];
+	triggerCharacters?: string[];
 
 	provideCompletionItems(model: editorCommon.IReadOnlyModel, position: Position, token: CancellationToken): ISuggestResult | Thenable<ISuggestResult>;
 
diff --git a/src/vs/editor/common/services/editorWorkerServiceImpl.ts b/src/vs/editor/common/services/editorWorkerServiceImpl.ts
index 15c2650d8cfb27eed5f3cc8951c6b9fd48011515..63c5af6992bb82d94e3a3bc12088a6289a11bb23 100644
--- a/src/vs/editor/common/services/editorWorkerServiceImpl.ts
+++ b/src/vs/editor/common/services/editorWorkerServiceImpl.ts
@@ -47,7 +47,6 @@ export class EditorWorkerServiceImpl implements IEditorWorkerService {
 			}
 		});
 		const completionProvider = modes.SuggestRegistry.register('*', <modes.ISuggestSupport>{
-			triggerCharacters: [],
 			provideCompletionItems: (model, position, token) => {
 				if (configurationService.lookup<boolean>('editor.wordBasedSuggestions').value) {
 					return this._workerManager.withWorker().then(client => client.textualSuggest(model.uri, position));
diff --git a/src/vs/editor/contrib/suggest/test/common/completionModel.test.ts b/src/vs/editor/contrib/suggest/test/common/completionModel.test.ts
index 1e464649c8208621776b650a7acfc94ad8b4435f..ee90794d46a4dbd17acfea93a163e901df82ea4f 100644
--- a/src/vs/editor/contrib/suggest/test/common/completionModel.test.ts
+++ b/src/vs/editor/contrib/suggest/test/common/completionModel.test.ts
@@ -31,7 +31,6 @@ suite('CompletionModel', function () {
 			};
 
 			support: ISuggestSupport = {
-				triggerCharacters: [],
 				provideCompletionItems(): any {
 					return;
 				}
@@ -98,7 +97,7 @@ suite('CompletionModel', function () {
 		assert.equal(model.incomplete, true);
 		assert.equal(model.items.length, 2);
 
-		const {complete, incomplete} = model.resolveIncompleteInfo();
+		const { complete, incomplete } = model.resolveIncompleteInfo();
 
 		assert.equal(incomplete.length, 1);
 		assert.ok(incomplete[0] === incompleteItem.support);
diff --git a/src/vs/editor/contrib/suggest/test/common/suggest.test.ts b/src/vs/editor/contrib/suggest/test/common/suggest.test.ts
index 45f07a09b687fbe832fc7b0cd4a1c1d2039f21f2..e4611538bd4504f60a7d26162c1ee16663715b92 100644
--- a/src/vs/editor/contrib/suggest/test/common/suggest.test.ts
+++ b/src/vs/editor/contrib/suggest/test/common/suggest.test.ts
@@ -22,7 +22,6 @@ suite('Suggest', function () {
 
 		model = Model.createFromString('FOO\nbar\BAR\nfoo', undefined, undefined, URI.parse('foo:bar/path'));
 		registration = SuggestRegistry.register({ pattern: 'bar/path' }, {
-			triggerCharacters: [],
 			provideCompletionItems() {
 				return {
 					incomplete: false,
@@ -108,4 +107,4 @@ suite('Suggest', function () {
 			assert.ok(items[0].support === foo);
 		});
 	});
-});
\ No newline at end of file
+});
diff --git a/src/vs/editor/contrib/suggest/test/common/suggestModel.test.ts b/src/vs/editor/contrib/suggest/test/common/suggestModel.test.ts
index 6143d956fdd722721173b8abcf728d2939c87e31..25339c5f59ec96e9a3834cfe515c3d7ba1a9f4ae 100644
--- a/src/vs/editor/contrib/suggest/test/common/suggestModel.test.ts
+++ b/src/vs/editor/contrib/suggest/test/common/suggestModel.test.ts
@@ -68,7 +68,6 @@ suite('SuggestModel - TriggerAndCancelOracle', function () {
 
 
 	const alwaysEmptySupport: ISuggestSupport = {
-		triggerCharacters: [],
 		provideCompletionItems(doc, pos) {
 			return <ISuggestResult>{
 				incomplete: false,
@@ -78,7 +77,6 @@ suite('SuggestModel - TriggerAndCancelOracle', function () {
 	};
 
 	const alwaysSomethingSupport: ISuggestSupport = {
-		triggerCharacters: [],
 		provideCompletionItems(doc, pos) {
 			return <ISuggestResult>{
 				currentWord: '',
@@ -224,7 +222,6 @@ suite('SuggestModel - TriggerAndCancelOracle', function () {
 	test('#17400: Keep filtering suggestModel.ts after space', function () {
 
 		disposables.push(SuggestRegistry.register({ scheme: 'test' }, {
-			triggerCharacters: [],
 			provideCompletionItems(doc, pos) {
 				return <ISuggestResult>{
 					currentWord: '',
diff --git a/src/vs/workbench/api/node/mainThreadLanguageFeatures.ts b/src/vs/workbench/api/node/mainThreadLanguageFeatures.ts
index 4a57ebc458ae0d54b4b5b9b585530eff3900f361..fff4d2338a94f53c1d9632f18d06c7f71a3bdcfc 100644
--- a/src/vs/workbench/api/node/mainThreadLanguageFeatures.ts
+++ b/src/vs/workbench/api/node/mainThreadLanguageFeatures.ts
@@ -225,7 +225,7 @@ export class MainThreadLanguageFeatures extends MainThreadLanguageFeaturesShape
 
 	$registerSuggestSupport(handle: number, selector: vscode.DocumentSelector, triggerCharacters: string[]): TPromise<any> {
 		this._registrations[handle] = modes.SuggestRegistry.register(selector, <modes.ISuggestSupport>{
-			triggerCharacters: triggerCharacters,
+			triggerCharacters,
 			provideCompletionItems: (model: IReadOnlyModel, position: EditorPosition, token: CancellationToken): Thenable<modes.ISuggestResult> => {
 				return this._heapService.trackRecursive(wireCancellationToken(token, this._proxy.$provideCompletionItems(handle, model.uri, position)));
 			},
diff --git a/src/vs/workbench/parts/snippets/electron-browser/snippetsService.ts b/src/vs/workbench/parts/snippets/electron-browser/snippetsService.ts
index 1c41fbfcf1e2389f624a5d0a312b3d80a06c2212..b0513b49c8bf1b6a55b07c0dc7baef8ba15bf760 100644
--- a/src/vs/workbench/parts/snippets/electron-browser/snippetsService.ts
+++ b/src/vs/workbench/parts/snippets/electron-browser/snippetsService.ts
@@ -43,7 +43,6 @@ class SnippetsService implements ISnippetsService {
 
 	constructor() {
 		setSnippetSuggestSupport({
-			triggerCharacters: undefined,
 			provideCompletionItems: (model, position) => {
 				const suggestions = this.getSnippetCompletions(<any>model, position);
 				return { suggestions };