diff --git a/src/vs/base/common/htmlContent.ts b/src/vs/base/common/htmlContent.ts
index 56f52a957ec..3943f6f8114 100644
--- a/src/vs/base/common/htmlContent.ts
+++ b/src/vs/base/common/htmlContent.ts
@@ -67,7 +67,7 @@ function markedStringEqual(a:MarkedString, b:MarkedString): boolean {
 	);
 }
 
-export function textToMarkedString(text: string) : MarkedString {
+export function textAsCodeBlock(text: string) : MarkedString {
 	return { language: 'string', value: text };
 }
 
diff --git a/src/vs/editor/common/services/modelServiceImpl.ts b/src/vs/editor/common/services/modelServiceImpl.ts
index c36c704bf4c..d9bd54ef51d 100644
--- a/src/vs/editor/common/services/modelServiceImpl.ts
+++ b/src/vs/editor/common/services/modelServiceImpl.ts
@@ -8,7 +8,7 @@ import * as nls from 'vs/nls';
 import network = require('vs/base/common/network');
 import Event, {Emitter} from 'vs/base/common/event';
 import {EmitterEvent} from 'vs/base/common/eventEmitter';
-import {MarkedString, textToMarkedString} from 'vs/base/common/htmlContent';
+import {MarkedString, textAsCodeBlock} from 'vs/base/common/htmlContent';
 import {IDisposable} from 'vs/base/common/lifecycle';
 import Severity from 'vs/base/common/severity';
 import URI from 'vs/base/common/uri';
@@ -121,7 +121,6 @@ class ModelMarkerHandler {
 		let className: string;
 		let color: string;
 		let darkColor: string;
-		let hoverMessage: MarkedString[] = null;
 
 		switch (marker.severity) {
 			case Severity.Ignore:
@@ -141,16 +140,24 @@ class ModelMarkerHandler {
 				break;
 		}
 
-		if (typeof marker.message === 'string') {
-			hoverMessage = [ textToMarkedString(marker.message) ];
-		} else if (Array.isArray(marker.message)) {
-			hoverMessage = <MarkedString[]><any>marker.message;
-		} else if (marker.message) {
-			hoverMessage = [ marker.message ];
-		}
+		let hoverMessage: MarkedString[] = null;
+		let {message, source} = marker;
 
-		if (hoverMessage && marker.source) {
-			hoverMessage.unshift(`[${marker.source}] `);
+		if (typeof message === 'string') {
+			if (source) {
+				message = nls.localize('sourceAndDiagMessage', "[{0}] {1}", source, message);
+			}
+			hoverMessage = [textAsCodeBlock(message)];
+		} else if (message) {
+			// this some old undocumented trick to get
+			// formatted error messages. no clue if we still
+			// have a need for that
+			hoverMessage = source ? [`[${marker.source}] `] : [];
+			if (Array.isArray(message)) {
+				hoverMessage.push(...(<any> message));
+			} else {
+				hoverMessage.push(message);
+			}
 		}
 
 		return {
diff --git a/src/vs/editor/contrib/goToDeclaration/browser/goToDeclaration.ts b/src/vs/editor/contrib/goToDeclaration/browser/goToDeclaration.ts
index 33e4861d11e..895923a27a6 100644
--- a/src/vs/editor/contrib/goToDeclaration/browser/goToDeclaration.ts
+++ b/src/vs/editor/contrib/goToDeclaration/browser/goToDeclaration.ts
@@ -9,7 +9,7 @@ import 'vs/css!./goToDeclaration';
 import * as nls from 'vs/nls';
 import {Throttler} from 'vs/base/common/async';
 import {onUnexpectedError} from 'vs/base/common/errors';
-import {MarkedString, textToMarkedString} from 'vs/base/common/htmlContent';
+import {MarkedString, textAsCodeBlock} from 'vs/base/common/htmlContent';
 import {KeyCode, KeyMod} from 'vs/base/common/keyCodes';
 import * as platform from 'vs/base/common/platform';
 import Severity from 'vs/base/common/severity';
@@ -385,7 +385,7 @@ class GotoDefinitionWithMouseEditorContribution implements editorCommon.IEditorC
 					value: text
 				};
 			} else {
-				hoverMessage = textToMarkedString(text);
+				hoverMessage = textAsCodeBlock(text);
 			}
 		}
 
diff --git a/src/vs/editor/contrib/hover/browser/modesContentHover.ts b/src/vs/editor/contrib/hover/browser/modesContentHover.ts
index 3b8e6f1b2a5..734b56205f1 100644
--- a/src/vs/editor/contrib/hover/browser/modesContentHover.ts
+++ b/src/vs/editor/contrib/hover/browser/modesContentHover.ts
@@ -20,7 +20,7 @@ import {ICodeEditor} from 'vs/editor/browser/editorBrowser';
 import {getHover} from '../common/hover';
 import {HoverOperation, IHoverComputer} from './hoverOperation';
 import {ContentHoverWidget} from './hoverWidgets';
-import {textToMarkedString, MarkedString} from 'vs/base/common/htmlContent';
+import {textAsCodeBlock, MarkedString} from 'vs/base/common/htmlContent';
 
 class ModesContentComputer implements IHoverComputer<Hover[]> {
 
@@ -112,7 +112,7 @@ class ModesContentComputer implements IHoverComputer<Hover[]> {
 	private _getLoadingMessage(): Hover {
 		return {
 			range: this._range,
-			contents: [textToMarkedString(nls.localize('modesContentHover.loading', "Loading..."))]
+			contents: [textAsCodeBlock(nls.localize('modesContentHover.loading', "Loading..."))]
 		};
 	}
 }