diff --git a/src/vs/base/browser/dom.ts b/src/vs/base/browser/dom.ts
index 40fa146233e..e31eedaaabd 100644
--- a/src/vs/base/browser/dom.ts
+++ b/src/vs/base/browser/dom.ts
@@ -691,10 +691,11 @@ export function getActiveElement(): Element | null {
 	return result;
 }
 
-export function createStyleSheet(container: HTMLElement = document.getElementsByTagName('head')[0]): HTMLStyleElement {
+export function createStyleSheet(container: HTMLElement = document.getElementsByTagName('head')[0], beforeAppend?: (style: HTMLStyleElement) => void): HTMLStyleElement {
 	const style = document.createElement('style');
 	style.type = 'text/css';
 	style.media = 'screen';
+	beforeAppend?.(style);
 	container.appendChild(style);
 	return style;
 }
diff --git a/src/vs/editor/standalone/browser/standaloneThemeService.ts b/src/vs/editor/standalone/browser/standaloneThemeService.ts
index 669791cecee..ec49af70ece 100644
--- a/src/vs/editor/standalone/browser/standaloneThemeService.ts
+++ b/src/vs/editor/standalone/browser/standaloneThemeService.ts
@@ -274,18 +274,20 @@ export class StandaloneThemeService extends Disposable implements IStandaloneThe
 
 	private _registerRegularEditorContainer(): IDisposable {
 		if (!this._globalStyleElement) {
-			this._globalStyleElement = dom.createStyleSheet();
-			this._globalStyleElement.className = 'monaco-colors';
-			this._globalStyleElement.textContent = this._allCSS;
+			this._globalStyleElement = dom.createStyleSheet(undefined, style => {
+				style.className = 'monaco-colors';
+				style.textContent = this._allCSS;
+			});
 			this._styleElements.push(this._globalStyleElement);
 		}
 		return Disposable.None;
 	}
 
 	private _registerShadowDomContainer(domNode: HTMLElement): IDisposable {
-		const styleElement = dom.createStyleSheet(domNode);
-		styleElement.className = 'monaco-colors';
-		styleElement.textContent = this._allCSS;
+		const styleElement = dom.createStyleSheet(domNode, style => {
+			style.className = 'monaco-colors';
+			style.textContent = this._allCSS;
+		});
 		this._styleElements.push(styleElement);
 		return {
 			dispose: () => {