diff --git a/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindReplaceWidget.ts b/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindReplaceWidget.ts
index 088c76bdb4bcdc05ccef48d966e27d36fecfe1fa..493ff8ed8cbed8ae8285b9f9597bfb2454201a58 100644
--- a/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindReplaceWidget.ts
+++ b/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindReplaceWidget.ts
@@ -402,13 +402,13 @@ export abstract class SimpleFindReplaceWidget extends Widget {
 
 	public hide(): void {
 		if (this._isVisible) {
-			dom.removeClass(this._domNode, 'visible-transition');
+			this._domNode.classList.remove('visible-transition');
 			this._domNode.setAttribute('aria-hidden', 'true');
 			// Need to delay toggling visibility until after Transition, then visibility hidden - removes from tabIndex list
 			setTimeout(() => {
 				this._isVisible = false;
 				this.updateButtons(this.foundMatch);
-				dom.removeClass(this._domNode, 'visible');
+				this._domNode.classList.remove('visible');
 			}, 200);
 		}
 	}
diff --git a/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindWidget.ts b/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindWidget.ts
index cb0d5ab2d5f4adc2b6eb5ac577dda234b636d2a2..18f496c77e868154113b5440b79b6cb705b1bd38 100644
--- a/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindWidget.ts
+++ b/src/vs/workbench/contrib/codeEditor/browser/find/simpleFindWidget.ts
@@ -235,13 +235,13 @@ export abstract class SimpleFindWidget extends Widget {
 
 	public hide(): void {
 		if (this._isVisible) {
-			dom.removeClass(this._innerDomNode, 'visible-transition');
+			this._innerDomNode.classList.remove('visible-transition');
 			this._innerDomNode.setAttribute('aria-hidden', 'true');
 			// Need to delay toggling visibility until after Transition, then visibility hidden - removes from tabIndex list
 			setTimeout(() => {
 				this._isVisible = false;
 				this.updateButtons(this.foundMatch);
-				dom.removeClass(this._innerDomNode, 'visible');
+				this._innerDomNode.classList.remove('visible');
 			}, 200);
 		}
 	}
diff --git a/src/vs/workbench/contrib/comments/browser/commentNode.ts b/src/vs/workbench/contrib/comments/browser/commentNode.ts
index 490a1a53d872891e5130476ccf7d2043e7502a1c..06a8cf9b42e95a820dc09c0f4dff7d6bbb2a2ac8 100644
--- a/src/vs/workbench/contrib/comments/browser/commentNode.ts
+++ b/src/vs/workbench/contrib/comments/browser/commentNode.ts
@@ -521,7 +521,7 @@ export class CommentNode extends Disposable {
 		if (!this._clearTimeout) {
 			dom.addClass(this.domNode, 'focus');
 			this._clearTimeout = setTimeout(() => {
-				dom.removeClass(this.domNode, 'focus');
+				this.domNode.classList.remove('focus');
 			}, 3000);
 		}
 	}
diff --git a/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts b/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
index d9403b06d8c1fac3bc922ba1bfdc791885a706f6..f379c44b583ab02f6336103320e11a76501ed55f 100644
--- a/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
+++ b/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
@@ -721,8 +721,8 @@ export class ReviewZoneWidget extends ZoneWidget implements ICommentThreadWidget
 		this._disposables.add(dom.addDisposableListener(this._reviewThreadReplyButton, 'focus', _ => this.expandReplyArea()));
 
 		this._commentEditor.onDidBlurEditorWidget(() => {
-			if (this._commentEditor.getModel()!.getValueLength() === 0 && this._commentForm.classList.add('expand')) {
-				dom.removeClass(this._commentForm, 'expand');
+			if (this._commentEditor.getModel()!.getValueLength() === 0 && this._commentForm.classList.contains('expand')) {
+				this._commentForm.classList.remove('expand');
 			}
 		});
 	}
diff --git a/src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts b/src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts
index 5fdb4c30007fa758155367a48c1e17ddc4b0ed5b..b803e39d664fec7292b56656fef2245244ee0722 100644
--- a/src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts
+++ b/src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts
@@ -1771,15 +1771,15 @@ export class NotebookEditorWidget extends Disposable implements INotebookEditor
 	}
 
 	toggleClassName(className: string) {
-		DOM.toggleClass(this._overlayContainer, className);
+		this._overlayContainer.classList.toggle(className);
 	}
 
 	addClassName(className: string) {
-		DOM.addClass(this._overlayContainer, className);
+		this._overlayContainer.classList.add(className);
 	}
 
 	removeClassName(className: string) {
-		DOM.removeClass(this._overlayContainer, className);
+		this._overlayContainer.classList.remove(className);
 	}
 
 
diff --git a/src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts b/src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts
index a30bdf629dc1093160cc8e6d7419df428cee58bc..22e63d148ba7783bbde0e166284210e854d46dd4 100644
--- a/src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts
+++ b/src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts
@@ -1083,9 +1083,9 @@ export class ListTopCellToolbar extends Disposable {
 
 	private updateClass() {
 		if (this.notebookEditor.viewModel?.length === 0) {
-			DOM.addClass(this.topCellToolbar, 'emptyNotebook');
+			this.topCellToolbar.classList.add('emptyNotebook');
 		} else {
-			DOM.removeClass(this.topCellToolbar, 'emptyNotebook');
+			this.topCellToolbar.classList.remove('emptyNotebook');
 		}
 	}
 
diff --git a/src/vs/workbench/contrib/notebook/browser/view/renderers/codeCell.ts b/src/vs/workbench/contrib/notebook/browser/view/renderers/codeCell.ts
index 8b534f2df4d347137ed95a513e8feac51b1c5f72..e19e4c443a449a359c278c40decdfdaad10a176d 100644
--- a/src/vs/workbench/contrib/notebook/browser/view/renderers/codeCell.ts
+++ b/src/vs/workbench/contrib/notebook/browser/view/renderers/codeCell.ts
@@ -233,7 +233,7 @@ export class CodeCell extends Disposable {
 
 			e.removed.forEach(options => {
 				if (options.className) {
-					DOM.removeClass(templateData.rootContainer, options.className);
+					templateData.rootContainer.classList.remove(options.className);
 				}
 
 				if (options.outputClassName) {
diff --git a/src/vs/workbench/contrib/notebook/browser/view/renderers/markdownCell.ts b/src/vs/workbench/contrib/notebook/browser/view/renderers/markdownCell.ts
index 51857bc9edc69ffcbd2bc910d36971ad1c25afcc..28d27b1f1d2fc7eacf6754ab90b3b9aa54fc31af 100644
--- a/src/vs/workbench/contrib/notebook/browser/view/renderers/markdownCell.ts
+++ b/src/vs/workbench/contrib/notebook/browser/view/renderers/markdownCell.ts
@@ -115,7 +115,7 @@ export class StatefulMarkdownCell extends Disposable {
 
 			e.removed.forEach(options => {
 				if (options.className) {
-					DOM.removeClass(templateData.rootContainer, options.className);
+					templateData.rootContainer.classList.remove(options.className);
 				}
 			});
 		}));