diff --git a/packages/loader/container-loader/src/container.ts b/packages/loader/container-loader/src/container.ts
index f9f55617b124..057c93f7f006 100644
--- a/packages/loader/container-loader/src/container.ts
+++ b/packages/loader/container-loader/src/container.ts
@@ -5,8 +5,6 @@
 
 // eslint-disable-next-line import/no-internal-modules
 import merge from "lodash/merge";
-// eslint-disable-next-line import/no-internal-modules
-import cloneDeep from "lodash/cloneDeep";
 
 import { v4 as uuid } from "uuid";
 import {
@@ -748,7 +746,12 @@ export class Container
 		// Prefix all events in this file with container-loader
 		this.mc = loggerToMonitoringContext(ChildLogger.create(this.subLogger, "Container"));
 
-		this.options = cloneDeep(this.loader.services.options);
+		// Warning: this is only a shallow clone. Mutation of any individual loader option will mutate it for
+		// all clients that were loaded from the same loader (including summarizer clients).
+		// Tracking alternative ways to handle this in AB#4129.
+		this.options = {
+			...this.loader.services.options,
+		};
 
 		this._deltaManager = this.createDeltaManager();
 
diff --git a/packages/test/test-end-to-end-tests/src/test/container.spec.ts b/packages/test/test-end-to-end-tests/src/test/container.spec.ts
index 425ec241f167..b2f56a145c5e 100644
--- a/packages/test/test-end-to-end-tests/src/test/container.spec.ts
+++ b/packages/test/test-end-to-end-tests/src/test/container.spec.ts
@@ -4,7 +4,6 @@
  */
 
 import { strict as assert } from "assert";
-import { v4 as uuid } from "uuid";
 import { MockDocumentDeltaConnection } from "@fluid-internal/test-loader-utils";
 import { IRequest } from "@fluidframework/core-interfaces";
 import {
@@ -12,7 +11,6 @@ import {
 	ContainerErrorType,
 	IFluidCodeDetails,
 	IContainer,
-	LoaderHeader,
 } from "@fluidframework/container-definitions";
 import {
 	ConnectionState,
@@ -50,7 +48,6 @@ import {
 import { IContainerRuntimeBase } from "@fluidframework/runtime-definitions";
 import { ConfigTypes, IConfigProviderBase } from "@fluidframework/telemetry-utils";
 import { ContainerRuntime } from "@fluidframework/container-runtime";
-import { IClient } from "@fluidframework/protocol-definitions";
 
 const id = "fluid-test://localhost/containerTest";
 const testRequest: IRequest = { url: id };
@@ -669,104 +666,6 @@ describeNoCompat("Container", (getTestObjectProvider) => {
 		assert.strictEqual(deltaManagerClosed, 1, "DeltaManager should send closed event");
 		assert.strictEqual(runtimeDispose, 1, "ContainerRuntime should send dispose event");
 	});
-
-	it("clientDetailsOverride does not cause client details of other containers with the same loader to change", async function () {
-		const documentId = uuid();
-		const client: IClient = {
-			details: {
-				capabilities: { interactive: true },
-			},
-			permission: [],
-			scopes: [],
-			user: { id: "" },
-			mode: "write",
-		};
-		const loaderProps: Partial<ILoaderProps> = {
-			options: {
-				client,
-			},
-		};
-		const loader = provider.makeTestLoader({ loaderProps });
-		const container1 = await loader.createDetachedContainer(provider.defaultCodeDetails);
-		const createNewRequest = provider.driver.createCreateNewRequest(documentId);
-		await container1.attach(createNewRequest);
-
-		// Check that client details are the expected ones before resolving a second container with different client details
-		assert.equal(
-			(container1 as any).clientDetails?.capabilities?.interactive,
-			true,
-			"First container's client capabilities should say 'interactive: true' before resolving second container",
-		);
-		assert.equal(
-			(container1 as any).clientDetails?.type,
-			undefined,
-			"First container's clientDetails should have undefined 'type' before resolving second container",
-		);
-
-		// Check that the IClient object passed in loader props hasn't been mutated
-		assert.equal(
-			client.details.capabilities.interactive,
-			true,
-			"IClient.details.capabilities.interactive should be 'true' before resolving second container",
-		);
-		assert.equal(
-			client.details.type,
-			undefined,
-			"IClient.details.type should be undefined before resolving second container",
-		);
-
-		// Resolve the container a second time with different client details.
-		// The contents of the [LoaderHeader.clientDetails] header end up in IContainerLoadOptions.clientDetailsOverride
-		// when loading the container during the loader.resolve() call.
-		const request: IRequest = {
-			headers: {
-				[LoaderHeader.cache]: false,
-				[LoaderHeader.clientDetails]: {
-					capabilities: { interactive: false },
-					type: "myContainerType",
-				},
-				[LoaderHeader.reconnect]: false,
-			},
-			url: await provider.driver.createContainerUrl(documentId, container1.resolvedUrl),
-		};
-		const container2 = await loader.resolve(request);
-
-		// Check that the second container's client details are the expected ones
-		assert.equal(
-			(container2 as any).clientDetails?.capabilities?.interactive,
-			false,
-			"Second container's capabilities should say 'interactive: false'",
-		);
-		assert.equal(
-			(container2 as any).clientDetails?.type,
-			"myContainerType",
-			"Second container's clientDetails say 'type: myContainerType'",
-		);
-
-		// Check that the first container's client details are still the expected ones after resolving the second container
-		assert.equal(
-			(container1 as any).clientDetails?.capabilities?.interactive,
-			true,
-			"First container's capabilities should say 'interactive: true' after resolving second container",
-		);
-		assert.equal(
-			(container1 as any).clientDetails?.type,
-			undefined,
-			"First container's clientDetails should have undefined 'type' after resolving second container",
-		);
-
-		// Check that the IClient object passed in loader props hasn't been mutated
-		assert.equal(
-			client.details.capabilities.interactive,
-			true,
-			"IClient.details.capabilities.interactive should be 'true' after resolving second container",
-		);
-		assert.equal(
-			client.details.type,
-			undefined,
-			"IClient.details.type should be undefined after resolving second container",
-		);
-	});
 });
 
 describeNoCompat("Driver", (getTestObjectProvider) => {