diff --git a/src/vs/workbench/api/browser/mainThreadCustomEditors.ts b/src/vs/workbench/api/browser/mainThreadCustomEditors.ts
index cd15f673c29..965e3089a96 100644
--- a/src/vs/workbench/api/browser/mainThreadCustomEditors.ts
+++ b/src/vs/workbench/api/browser/mainThreadCustomEditors.ts
@@ -44,6 +44,7 @@ import { ResourceWorkingCopy } from '../../services/workingCopy/common/resourceW
 import { IWorkingCopy, IWorkingCopyBackup, IWorkingCopySaveEvent, NO_TYPE_ID, WorkingCopyCapabilities } from '../../services/workingCopy/common/workingCopy.js';
 import { IWorkingCopyFileService, WorkingCopyFileEvent } from '../../services/workingCopy/common/workingCopyFileService.js';
 import { IWorkingCopyService } from '../../services/workingCopy/common/workingCopyService.js';
+import { IUriIdentityService } from '../../../platform/uriIdentity/common/uriIdentity.js';
 
 const enum CustomEditorModelType {
 	Custom,
@@ -73,6 +74,7 @@ export class MainThreadCustomEditors extends Disposable implements extHostProtoc
 		@IEditorService private readonly _editorService: IEditorService,
 		@IInstantiationService private readonly _instantiationService: IInstantiationService,
 		@IWebviewWorkbenchService private readonly _webviewWorkbenchService: IWebviewWorkbenchService,
+		@IUriIdentityService private readonly _uriIdentityService: IUriIdentityService,
 	) {
 		super();
 
@@ -197,7 +199,7 @@ export class MainThreadCustomEditors extends Disposable implements extHostProtoc
 				}
 
 				try {
-					await this._proxyCustomEditors.$resolveCustomEditor(resource, handle, viewType, {
+					await this._proxyCustomEditors.$resolveCustomEditor(this._uriIdentityService.asCanonicalUri(resource), handle, viewType, {
 						title: webviewInput.getTitle(),
 						contentOptions: webviewInput.webview.contentOptions,
 						options: webviewInput.webview.options,
diff --git a/src/vs/workbench/contrib/customEditor/browser/customEditors.ts b/src/vs/workbench/contrib/customEditor/browser/customEditors.ts
index 464f9a8cb19..d9bd443af2c 100644
--- a/src/vs/workbench/contrib/customEditor/browser/customEditors.ts
+++ b/src/vs/workbench/contrib/customEditor/browser/customEditors.ts
@@ -21,7 +21,7 @@ import { IUriIdentityService } from '../../../../platform/uriIdentity/common/uri
 import { DEFAULT_EDITOR_ASSOCIATION, EditorExtensions, GroupIdentifier, IEditorFactoryRegistry, IResourceDiffEditorInput } from '../../../common/editor.js';
 import { DiffEditorInput } from '../../../common/editor/diffEditorInput.js';
 import { EditorInput } from '../../../common/editor/editorInput.js';
-import { CONTEXT_ACTIVE_CUSTOM_EDITOR_ID, CONTEXT_FOCUSED_CUSTOM_EDITOR_IS_EDITABLE, CustomEditorCapabilities, CustomEditorInfo, CustomEditorInfoCollection, ICustomEditorService } from '../common/customEditor.js';
+import { CONTEXT_ACTIVE_CUSTOM_EDITOR_ID, CONTEXT_FOCUSED_CUSTOM_EDITOR_IS_EDITABLE, CustomEditorCapabilities, CustomEditorInfo, CustomEditorInfoCollection, ICustomEditorModelManager, ICustomEditorService } from '../common/customEditor.js';
 import { CustomEditorModelManager } from '../common/customEditorModelManager.js';
 import { IEditorGroup, IEditorGroupContextKeyProvider, IEditorGroupsService } from '../../../services/editor/common/editorGroupsService.js';
 import { IEditorResolverService, IEditorType, RegisteredEditorPriority } from '../../../services/editor/common/editorResolverService.js';
@@ -37,7 +37,7 @@ export class CustomEditorService extends Disposable implements ICustomEditorServ
 	private readonly _editorResolverDisposables = this._register(new DisposableStore());
 	private readonly _editorCapabilities = new Map<string, CustomEditorCapabilities>();
 
-	private readonly _models = new CustomEditorModelManager();
+	private readonly _models: ICustomEditorModelManager;
 
 	private readonly _onDidChangeEditorTypes = this._register(new Emitter<void>());
 	public readonly onDidChangeEditorTypes: Event<void> = this._onDidChangeEditorTypes.event;
@@ -55,6 +55,8 @@ export class CustomEditorService extends Disposable implements ICustomEditorServ
 	) {
 		super();
 
+		this._models = new CustomEditorModelManager(this.uriIdentityService);
+
 		this._contributedEditors = this._register(new ContributedCustomEditors(storageService));
 		// Register the contribution points only emitting one change from the resolver
 		this.editorResolverService.bufferChangeEvents(this.registerContributionPoints.bind(this));
diff --git a/src/vs/workbench/contrib/customEditor/common/customEditorModelManager.ts b/src/vs/workbench/contrib/customEditor/common/customEditorModelManager.ts
index 66d5b2b5989..7b5219d5e07 100644
--- a/src/vs/workbench/contrib/customEditor/common/customEditorModelManager.ts
+++ b/src/vs/workbench/contrib/customEditor/common/customEditorModelManager.ts
@@ -6,9 +6,17 @@
 import { createSingleCallFunction } from '../../../../base/common/functional.js';
 import { IReference } from '../../../../base/common/lifecycle.js';
 import { URI } from '../../../../base/common/uri.js';
+import { IUriIdentityService } from '../../../../platform/uriIdentity/common/uriIdentity.js';
 import { ICustomEditorModel, ICustomEditorModelManager } from './customEditor.js';
 
 export class CustomEditorModelManager implements ICustomEditorModelManager {
+	private readonly _uriIdentityService: IUriIdentityService;
+
+	constructor(
+		uriIdentityService: IUriIdentityService,
+	) {
+		this._uriIdentityService = uriIdentityService;
+	}
 
 	private readonly _references = new Map<string, {
 		readonly viewType: string;
@@ -76,6 +84,7 @@ export class CustomEditorModelManager implements ICustomEditorModelManager {
 	}
 
 	private key(resource: URI, viewType: string): string {
+		resource = this._uriIdentityService.asCanonicalUri(resource);
 		return `${resource.toString()}@@@${viewType}`;
 	}
 }