diff --git a/src/vs/workbench/api/browser/mainThreadLanguageFeatures.ts b/src/vs/workbench/api/browser/mainThreadLanguageFeatures.ts
index fd9e89a6536..088ccde1823 100644
--- a/src/vs/workbench/api/browser/mainThreadLanguageFeatures.ts
+++ b/src/vs/workbench/api/browser/mainThreadLanguageFeatures.ts
@@ -34,6 +34,7 @@ import * as typeh from 'vs/workbench/contrib/typeHierarchy/common/typeHierarchy'
 import { extHostNamedCustomer, IExtHostContext } from 'vs/workbench/services/extensions/common/extHostCustomers';
 import { ExtHostContext, ExtHostLanguageFeaturesShape, ICallHierarchyItemDto, ICodeActionDto, ICodeActionProviderMetadataDto, IdentifiableInlineCompletion, IdentifiableInlineCompletions, IDocumentDropEditProviderMetadata, IDocumentFilterDto, IIndentationRuleDto, IInlayHintDto, ILanguageConfigurationDto, ILanguageWordDefinitionDto, ILinkDto, ILocationDto, ILocationLinkDto, IOnEnterRuleDto, IPasteEditProviderMetadataDto, IRegExpDto, ISignatureHelpProviderMetadataDto, ISuggestDataDto, ISuggestDataDtoField, ISuggestResultDtoField, ITypeHierarchyItemDto, IWorkspaceSymbolDto, MainContext, MainThreadLanguageFeaturesShape } from '../common/extHost.protocol';
 import { USUAL_WORD_SEPARATORS } from 'vs/editor/common/core/wordHelper';
+import { isFalsyOrEmpty } from 'vs/base/common/arrays';
 
 @extHostNamedCustomer(MainContext.MainThreadLanguageFeatures)
 export class MainThreadLanguageFeatures extends Disposable implements MainThreadLanguageFeaturesShape {
@@ -308,15 +309,12 @@ export class MainThreadLanguageFeatures extends Disposable implements MainThread
 					});
 
 					const res = this._proxy.$provideDocumentHighlights(handle, model.uri, position, token);
-					if (!res) {
-						return Promise.resolve(new Map<URI, languages.DocumentHighlight[]>());
-					}
-
 					return res.then(data => {
 						const result = new Map<URI, languages.DocumentHighlight[]>();
-						if (data) {
-							result.set(model.uri, data);
+						if (isFalsyOrEmpty(data) || !data) {
+							return result;
 						}
+						result.set(model.uri, data);
 
 						if (!word) {
 							return result;