diff --git a/client/src/common/client.ts b/client/src/common/client.ts
index 106a5f91b..4564bf4ac 100644
--- a/client/src/common/client.ts
+++ b/client/src/common/client.ts
@@ -655,7 +655,7 @@ export abstract class BaseLanguageClient implements FeatureClient<Middleware, La
 		try {
 			// Ensure we have a connection before we force the document sync.
 			const connection = await this.$start();
-			this.forceDocumentSync();
+			await this.forceDocumentSync();
 			return connection.sendRequest<R>(type, ...params);
 		} catch (error) {
 			this.error(`Sending request ${Is.string(type) ? type : type.method} failed.`, error);
@@ -718,7 +718,7 @@ export abstract class BaseLanguageClient implements FeatureClient<Middleware, La
 		try {
 			// Ensure we have a connection before we force the document sync.
 			const connection = await this.$start();
-			this.forceDocumentSync();
+			await this.forceDocumentSync();
 			return connection.sendNotification(type, params);
 		} catch (error) {
 			this.error(`Sending notification ${Is.string(type) ? type : type.method} failed.`, error);
@@ -1324,7 +1324,7 @@ export abstract class BaseLanguageClient implements FeatureClient<Middleware, La
 			client._fileEvents.push(event);
 			return client._fileEventDelayer.trigger(async (): Promise<void> => {
 				const connection = await client.$start();
-				client.forceDocumentSync();
+				await client.forceDocumentSync();
 				const result = connection.sendNotification(DidChangeWatchedFilesNotification.type, { changes: client._fileEvents });
 				client._fileEvents = [];
 				return result;
@@ -1337,11 +1337,11 @@ export abstract class BaseLanguageClient implements FeatureClient<Middleware, La
 	}
 
 	private _didChangeTextDocumentFeature: DidChangeTextDocumentFeature | undefined;
-	private forceDocumentSync(): void {
+	private async forceDocumentSync(): Promise<void> {
 		if (this._didChangeTextDocumentFeature === undefined) {
 			this._didChangeTextDocumentFeature = this._dynamicFeatures.get(DidChangeTextDocumentNotification.type.method) as DidChangeTextDocumentFeature;
 		}
-		this._didChangeTextDocumentFeature.forceDelivery();
+		return this._didChangeTextDocumentFeature.forceDelivery();
 	}
 
 	private _diagnosticQueue: Map<string, Diagnostic[]> = new Map();
diff --git a/client/src/common/textSynchronization.ts b/client/src/common/textSynchronization.ts
index 055842bb1..041e36ac2 100644
--- a/client/src/common/textSynchronization.ts
+++ b/client/src/common/textSynchronization.ts
@@ -176,7 +176,7 @@ export class DidChangeTextDocumentFeature extends DynamicDocumentFeature<TextDoc
 	private _listener: Disposable | undefined;
 	private readonly _changeData: Map<string, DidChangeTextDocumentData>;
 	private _forcingDelivery: boolean = false;
-	private _changeDelayer: { uri: string; delayer: Delayer<void> } | undefined;
+	private _changeDelayer: { uri: string; delayer: Delayer<Promise<void>> } | undefined;
 	private readonly _onNotificationSent: EventEmitter<NotificationSendEvent<TextDocumentChangeEvent, DidChangeTextDocumentParams>>;
 
 	constructor(client: FeatureClient<TextDocumentSynchronizationMiddleware>) {
@@ -253,15 +253,23 @@ export class DidChangeTextDocumentFeature extends DynamicDocumentFeature<TextDoc
 						if (this._changeDelayer) {
 							if (this._changeDelayer.uri !== event.document.uri.toString()) {
 								// Use this force delivery to track boolean state. Otherwise we might call two times.
-								this.forceDelivery();
+								await this.forceDelivery();
 								this._changeDelayer.uri = event.document.uri.toString();
 							}
+							// Usually we return the promise that signals that the data has been
+							// handed of to the network. With delayed change notification we can't
+							// do that since it would make the sendNotification call wait until the
+							// change delayer resolves and would therefore defeat the purpose. We
+							// instead return the change delayer and ensure via forceDocumentSync
+							// that before sending other notification / request the document sync
+							// has actually happened.
 							return this._changeDelayer.delayer.trigger(() => doSend(event));
 						} else {
 							this._changeDelayer = {
 								uri: event.document.uri.toString(),
-								delayer: new Delayer<void>(200)
+								delayer: new Delayer<Promise<void>>(200)
 							};
+							// See comment above.
 							return this._changeDelayer.delayer.trigger(() => doSend(event), -1);
 						}
 					};
@@ -304,13 +312,13 @@ export class DidChangeTextDocumentFeature extends DynamicDocumentFeature<TextDoc
 		}
 	}
 
-	public forceDelivery() {
+	public async forceDelivery(): Promise<void> {
 		if (this._forcingDelivery || !this._changeDelayer) {
 			return;
 		}
 		try {
 			this._forcingDelivery = true;
-			this._changeDelayer.delayer.forceDelivery();
+			return this._changeDelayer.delayer.forceDelivery();
 		} finally {
 			this._forcingDelivery = false;
 		}
diff --git a/testbed/server/src/server.ts b/testbed/server/src/server.ts
index 4ea360472..4d8d15eb0 100644
--- a/testbed/server/src/server.ts
+++ b/testbed/server/src/server.ts
@@ -124,7 +124,8 @@ connection.onInitialize((params, cancel, progress): Thenable<InitializeResult> |
 				textDocumentSync: TextDocumentSyncKind.Full,
 				hoverProvider: true,
 				completionProvider: {
-					allCommitCharacters: ['.', ','],
+					triggerCharacters: ['.'],
+					allCommitCharacters: [';'],
 					resolveProvider: false,
 				},
 				signatureHelpProvider: {