diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 8d3b6988fb1..d655abe4e72 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -274,6 +274,12 @@ export interface ISerializedSignatureHelpProviderMetadata {
 	readonly retriggerCharacters: ReadonlyArray<string>;
 }
 
+export interface IMarkdownStringDto {
+	isTrusted: boolean;
+	value: string;
+	uris: { [n: string]: UriComponents };
+}
+
 export interface MainThreadLanguageFeaturesShape extends IDisposable {
 	$unregister(handle: number): void;
 	$registerOutlineSupport(handle: number, selector: ISerializedDocumentFilter[], extensionId: string): void;
diff --git a/src/vs/workbench/api/node/extHostLanguageFeatures.ts b/src/vs/workbench/api/node/extHostLanguageFeatures.ts
index fd9a617a2e2..1d1608d34c9 100644
--- a/src/vs/workbench/api/node/extHostLanguageFeatures.ts
+++ b/src/vs/workbench/api/node/extHostLanguageFeatures.ts
@@ -664,7 +664,7 @@ class SuggestAdapter {
 			label: item.label,
 			kind: typeConvert.CompletionItemKind.from(item.kind),
 			detail: item.detail,
-			documentation: item.documentation,
+			documentation: typeConvert.MarkdownString.from(item.documentation),
 			filterText: item.filterText,
 			sortText: item.sortText,
 			preselect: item.preselect,
diff --git a/src/vs/workbench/api/node/extHostTypeConverters.ts b/src/vs/workbench/api/node/extHostTypeConverters.ts
index de2d33911d8..7db09363924 100644
--- a/src/vs/workbench/api/node/extHostTypeConverters.ts
+++ b/src/vs/workbench/api/node/extHostTypeConverters.ts
@@ -19,11 +19,12 @@ import { IRange } from 'vs/editor/common/core/range';
 import { ISelection } from 'vs/editor/common/core/selection';
 import * as htmlContent from 'vs/base/common/htmlContent';
 import * as languageSelector from 'vs/editor/common/modes/languageSelector';
-import { WorkspaceEditDto, ResourceTextEditDto, ResourceFileEditDto } from 'vs/workbench/api/node/extHost.protocol';
+import { WorkspaceEditDto, ResourceTextEditDto, ResourceFileEditDto, IMarkdownStringDto } from 'vs/workbench/api/node/extHost.protocol';
 import { MarkerSeverity, IRelatedInformation, IMarkerData, MarkerTag } from 'vs/platform/markers/common/markers';
 import { ACTIVE_GROUP, SIDE_GROUP } from 'vs/workbench/services/editor/common/editorService';
 import { ExtHostDocumentsAndEditors } from 'vs/workbench/api/node/extHostDocumentsAndEditors';
 import { isString, isNumber } from 'vs/base/common/types';
+import * as marked from 'vs/base/common/marked/marked';
 
 export interface PositionLike {
 	line: number;
@@ -220,6 +221,29 @@ export namespace MarkdownString {
 			return { value: '' };
 		}
 	}
+
+	export function from2(markup: vscode.MarkedString | vscode.MarkdownString): IMarkdownStringDto {
+		let { value, isTrusted } = from(markup);
+
+		let uris = Object.create(null);
+		let renderer = new marked.Renderer();
+
+		renderer.image = renderer.link = (href: string): string => {
+			try {
+				uris[href] = URI.parse(href, true);
+			} catch (e) {
+				// ignore
+			}
+			return '';
+		};
+		marked(value, { renderer });
+		return {
+			isTrusted,
+			value,
+			uris
+		};
+	}
+
 	export function to(value: htmlContent.IMarkdownString): vscode.MarkdownString {
 		const ret = new htmlContent.MarkdownString(value.value);
 		ret.isTrusted = value.isTrusted;