diff --git a/src/Components/Web.JS/src/Boot.WebAssembly.Common.ts b/src/Components/Web.JS/src/Boot.WebAssembly.Common.ts
index 6740dd9a84e9..7efd32e495f4 100644
--- a/src/Components/Web.JS/src/Boot.WebAssembly.Common.ts
+++ b/src/Components/Web.JS/src/Boot.WebAssembly.Common.ts
@@ -2,13 +2,13 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 /* eslint-disable array-element-newline */
-import { DotNet } from '@microsoft/dotnet-js-interop';
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
 import { Blazor } from './GlobalExports';
 import * as Environment from './Environment';
-import { BINDING, monoPlatform, dispatcher, getInitializer } from './Platform/Mono/MonoPlatform';
+import { monoPlatform, dispatcher, getInitializer } from './Platform/Mono/MonoPlatform';
 import { renderBatch, getRendererer, attachRootComponentToElement, attachRootComponentToLogicalElement } from './Rendering/Renderer';
 import { SharedMemoryRenderBatch } from './Rendering/RenderBatch/SharedMemoryRenderBatch';
-import { PlatformApi, Pointer } from './Platform/Platform';
+import { Pointer } from './Platform/Platform';
 import { WebAssemblyStartOptions } from './Platform/WebAssemblyStartOptions';
 import { addDispatchEventMiddleware } from './Rendering/WebRendererInteropMethods';
 import { WebAssemblyComponentDescriptor, discoverWebAssemblyPersistedState } from './Services/ComponentDescriptorDiscovery';
@@ -19,7 +19,6 @@ import { RootComponentManager } from './Services/RootComponentManager';
 import { WebRendererId } from './Rendering/WebRendererId';
 
 let options: Partial<WebAssemblyStartOptions> | undefined;
-let initializersPromise: Promise<void>;
 let platformLoadPromise: Promise<void> | undefined;
 let loadedWebAssemblyPlatform = false;
 let started = false;
@@ -43,7 +42,7 @@ export function resolveInitialUpdate(value: string): void {
 }
 
 let resolveInitializersPromise: (value: void) => void;
-initializersPromise = new Promise<void>(resolve => {
+const initializersPromise = new Promise<void>(resolve => {
   resolveInitializersPromise = resolve;
 });
 
@@ -105,7 +104,6 @@ async function startCore(components: RootComponentManager<WebAssemblyComponentDe
   Blazor._internal.getApplyUpdateCapabilities = () => dispatcher.invokeDotNetStaticMethod('Microsoft.AspNetCore.Components.WebAssembly', 'GetApplyUpdateCapabilities');
 
   // Configure JS interop
-  Blazor._internal.invokeJSFromDotNet = invokeJSFromDotNet;
   Blazor._internal.invokeJSJson = invokeJSJson;
   Blazor._internal.endInvokeDotNetFromJS = endInvokeDotNetFromJS;
   Blazor._internal.receiveWebAssemblyDotNetDataStream = receiveWebAssemblyDotNetDataStream;
@@ -169,7 +167,7 @@ async function startCore(components: RootComponentManager<WebAssemblyComponentDe
   Blazor._internal.endUpdateRootComponents = (batchId: number) =>
     components.onAfterUpdateRootComponents?.(batchId);
 
-  Blazor._internal.attachRootComponentToElement = (selector, componentId, rendererId: any) => {
+  Blazor._internal.attachRootComponentToElement = (selector, componentId, rendererId) => {
     const element = componentAttacher.resolveRegisteredElement(selector);
     if (!element) {
       attachRootComponentToElement(selector, componentId, rendererId);
@@ -178,17 +176,16 @@ async function startCore(components: RootComponentManager<WebAssemblyComponentDe
     }
   };
 
-  let api: PlatformApi;
   try {
     await platformLoadPromise;
-    api = await platform.start();
+    await platform.start();
   } catch (ex) {
     throw new Error(`Failed to start platform. Reason: ${ex}`);
   }
 
   // Start up the application
   platform.callEntryPoint();
-  // At this point .NET has been initialized (and has yielded), we can't await the promise becasue it will
+  // At this point .NET has been initialized (and has yielded), we can't await the promise because it will
   // only end when the app finishes running
   const initializer = getInitializer();
   initializer.invokeAfterStartedCallbacks(Blazor);
@@ -229,45 +226,6 @@ export function hasLoadedWebAssemblyPlatform(): boolean {
   return loadedWebAssemblyPlatform;
 }
 
-// obsolete, legacy, don't use for new code!
-function invokeJSFromDotNet(callInfo: Pointer, arg0: any, arg1: any, arg2: any): any {
-  const functionIdentifier = monoPlatform.readStringField(callInfo, 0)!;
-  const resultType = monoPlatform.readInt32Field(callInfo, 4);
-  const marshalledCallArgsJson = monoPlatform.readStringField(callInfo, 8);
-  const targetInstanceId = monoPlatform.readUint64Field(callInfo, 20);
-
-  if (marshalledCallArgsJson !== null) {
-    const marshalledCallAsyncHandle = monoPlatform.readUint64Field(callInfo, 12);
-
-    if (marshalledCallAsyncHandle !== 0) {
-      dispatcher.beginInvokeJSFromDotNet(marshalledCallAsyncHandle, functionIdentifier, marshalledCallArgsJson, resultType, targetInstanceId);
-      return 0;
-    } else {
-      const resultJson = dispatcher.invokeJSFromDotNet(functionIdentifier, marshalledCallArgsJson, resultType, targetInstanceId)!;
-      return resultJson === null ? 0 : BINDING.js_string_to_mono_string(resultJson);
-    }
-  } else {
-    const func = DotNet.findJSFunction(functionIdentifier, targetInstanceId);
-    const result = func.call(null, arg0, arg1, arg2);
-
-    switch (resultType) {
-      case DotNet.JSCallResultType.Default:
-        return result;
-      case DotNet.JSCallResultType.JSObjectReference:
-        return DotNet.createJSObjectReference(result).__jsObjectId;
-      case DotNet.JSCallResultType.JSStreamReference: {
-        const streamReference = DotNet.createJSStreamReference(result);
-        const resultJson = JSON.stringify(streamReference);
-        return BINDING.js_string_to_mono_string(resultJson);
-      }
-      case DotNet.JSCallResultType.JSVoidResult:
-        return null;
-      default:
-        throw new Error(`Invalid JS call result type '${resultType}'.`);
-    }
-  }
-}
-
 export function updateWebAssemblyRootComponents(operations: string): void {
   if (!startPromise) {
     throw new Error('Blazor WebAssembly has not started.');
@@ -307,7 +265,7 @@ function endInvokeDotNetFromJS(callId: string, success: boolean, resultJsonOrErr
   dispatcher.endInvokeDotNetFromJS(callId, success, resultJsonOrErrorMessage);
 }
 
-function receiveWebAssemblyDotNetDataStream(streamId: number, data: any, bytesRead: number, errorMessage: string): void {
+function receiveWebAssemblyDotNetDataStream(streamId: number, data: Uint8Array, bytesRead: number, errorMessage: string): void {
   receiveDotNetDataStream(dispatcher, streamId, data, bytesRead, errorMessage);
 }
 
diff --git a/src/Components/Web.JS/src/Boot.WebAssembly.ts b/src/Components/Web.JS/src/Boot.WebAssembly.ts
index bd8e556096d6..ca1523f60f1c 100644
--- a/src/Components/Web.JS/src/Boot.WebAssembly.ts
+++ b/src/Components/Web.JS/src/Boot.WebAssembly.ts
@@ -3,7 +3,6 @@
 
 /* eslint-disable array-element-newline */
 import { Blazor } from './GlobalExports';
-import { Module } from './Platform/Mono/MonoPlatform';
 import { shouldAutoStart } from './BootCommon';
 import { WebAssemblyStartOptions } from './Platform/WebAssemblyStartOptions';
 import { setWebAssemblyOptions, startWebAssembly } from './Boot.WebAssembly.Common';
@@ -11,6 +10,7 @@ import { WebAssemblyComponentDescriptor, discoverComponents } from './Services/C
 import { DotNet } from '@microsoft/dotnet-js-interop';
 import { InitialRootComponentsList } from './Services/InitialRootComponentsList';
 import { JSEventRegistry } from './Services/JSEventRegistry';
+import { printErr } from './Platform/Mono/MonoPlatform';
 
 let started = false;
 
@@ -32,13 +32,5 @@ Blazor.start = boot;
 window['DotNet'] = DotNet;
 
 if (shouldAutoStart()) {
-  boot().catch(error => {
-    if (typeof Module !== 'undefined' && Module.err) {
-      // Logs it, and causes the error UI to appear
-      Module.err(error);
-    } else {
-      // The error must have happened so early we didn't yet set up the error UI, so just log to console
-      console.error(error);
-    }
-  });
+  boot().catch(printErr);
 }
diff --git a/src/Components/Web.JS/src/GlobalExports.ts b/src/Components/Web.JS/src/GlobalExports.ts
index 52c3dec4d0e6..fad0d11cc42e 100644
--- a/src/Components/Web.JS/src/GlobalExports.ts
+++ b/src/Components/Web.JS/src/GlobalExports.ts
@@ -52,7 +52,6 @@ export interface IBlazor {
     forceCloseConnection?: () => Promise<void>;
     InputFile?: typeof InputFile;
     NavigationLock: typeof NavigationLock;
-    invokeJSFromDotNet?: (callInfo: Pointer, arg0: any, arg1: any, arg2: any) => any;
     invokeJSJson?: (identifier: string, targetInstanceId: number, resultType: number, argsJson: string, asyncHandle: number) => string | null;
     endInvokeDotNetFromJS?: (callId: string, success: boolean, resultJsonOrErrorMessage: string) => void;
     receiveByteArray?: (id: number, data: Uint8Array) => void;
diff --git a/src/Components/Web.JS/src/Platform/Mono/MonoPlatform.ts b/src/Components/Web.JS/src/Platform/Mono/MonoPlatform.ts
index 31c0cba1b6e7..8b31c404b74b 100644
--- a/src/Components/Web.JS/src/Platform/Mono/MonoPlatform.ts
+++ b/src/Components/Web.JS/src/Platform/Mono/MonoPlatform.ts
@@ -10,55 +10,22 @@ import { showErrorNotification } from '../../BootErrors';
 import { Platform, System_Array, Pointer, System_Object, System_String, HeapLock, PlatformApi } from '../Platform';
 import { WebAssemblyBootResourceType, WebAssemblyStartOptions } from '../WebAssemblyStartOptions';
 import { Blazor } from '../../GlobalExports';
-import { DotnetModuleConfig, EmscriptenModule, MonoConfig, ModuleAPI, RuntimeAPI, GlobalizationMode } from 'dotnet-runtime';
-import { BINDINGType, MONOType } from 'dotnet-runtime/dotnet-legacy';
+import { DotnetModuleConfig, MonoConfig, ModuleAPI, RuntimeAPI, GlobalizationMode } from 'dotnet-runtime';
 import { fetchAndInvokeInitializers } from '../../JSInitializers/JSInitializers.WebAssembly';
 import { JSInitializer } from '../../JSInitializers/JSInitializers';
-import { WebRendererId } from '../../Rendering/WebRendererId';
 
 // initially undefined and only fully initialized after createEmscriptenModuleInstance()
-export let BINDING: BINDINGType = undefined as any;
-export let MONO: MONOType = undefined as any;
-export let Module: DotnetModuleConfig & EmscriptenModule = undefined as any;
 export let dispatcher: DotNet.ICallDispatcher = undefined as any;
 let MONO_INTERNAL: any = undefined as any;
 let runtime: RuntimeAPI = undefined as any;
 let jsInitializer: JSInitializer;
 
-const uint64HighOrderShift = Math.pow(2, 32);
-const maxSafeNumberHighPart = Math.pow(2, 21) - 1; // The high-order int32 from Number.MAX_SAFE_INTEGER
-
 let currentHeapLock: MonoHeapLock | null = null;
 
-// Memory access helpers
-// The implementations are exactly equivalent to what the global getValue(addr, type) function does,
-// except without having to parse the 'type' parameter, and with less risk of mistakes at the call site
-function getValueI16(ptr: number) {
-  return MONO.getI16(ptr);
-}
-function getValueI32(ptr: number) {
-  return MONO.getI32(ptr);
-}
-function getValueFloat(ptr: number) {
-  return MONO.getF32(ptr);
-}
-
 export function getInitializer() {
   return jsInitializer;
 }
 
-function getValueU64(ptr: number) {
-  // There is no Module.HEAPU64, and Module.getValue(..., 'i64') doesn't work because the implementation
-  // treats 'i64' as being the same as 'i32'. Also we must take care to read both halves as unsigned.
-  const heapU32Index = ptr >> 2;
-  const highPart = Module.HEAPU32[heapU32Index + 1];
-  if (highPart > maxSafeNumberHighPart) {
-    throw new Error(`Cannot read uint64 with high order part ${highPart}, because the result would exceed Number.MAX_SAFE_INTEGER.`);
-  }
-
-  return (highPart * uint64HighOrderShift) + Module.HEAPU32[heapU32Index];
-}
-
 export const monoPlatform: Platform = {
   load: function load(options: Partial<WebAssemblyStartOptions>, onConfigLoaded?: (loadedConfig: MonoConfig) => void) {
     return createRuntimeInstance(options, onConfigLoaded);
@@ -77,18 +44,6 @@ export const monoPlatform: Platform = {
     }
   },
 
-  toUint8Array: function toUint8Array(array: System_Array<any>): Uint8Array {
-    const dataPtr = getArrayDataPointer(array);
-    const length = getValueI32(dataPtr);
-    const uint8Array = new Uint8Array(length);
-    uint8Array.set(Module.HEAPU8.subarray(dataPtr + 4, dataPtr + 4 + length));
-    return uint8Array;
-  },
-
-  getArrayLength: function getArrayLength(array: System_Array<any>): number {
-    return getValueI32(getArrayDataPointer(array));
-  },
-
   getArrayEntryPtr: function getArrayEntryPtr<TPtr extends Pointer>(array: System_Array<TPtr>, index: number, itemSize: number): TPtr {
     // First byte is array length, followed by entries
     const address = getArrayDataPointer(array) + 4 + index * itemSize;
@@ -97,31 +52,27 @@ export const monoPlatform: Platform = {
 
   getObjectFieldsBaseAddress: function getObjectFieldsBaseAddress(referenceTypedObject: System_Object): Pointer {
     // The first two int32 values are internal Mono data
-    return (referenceTypedObject as any as number + 8) as any as Pointer;
+    return (referenceTypedObject as any + 8) as any as Pointer;
   },
 
   readInt16Field: function readHeapInt16(baseAddress: Pointer, fieldOffset?: number): number {
-    return getValueI16((baseAddress as any as number) + (fieldOffset || 0));
+    return runtime.getHeapI16((baseAddress as any) + (fieldOffset || 0));
   },
 
   readInt32Field: function readHeapInt32(baseAddress: Pointer, fieldOffset?: number): number {
-    return getValueI32((baseAddress as unknown as number) + (fieldOffset || 0));
+    return runtime.getHeapI32((baseAddress as any) + (fieldOffset || 0));
   },
 
   readUint64Field: function readHeapUint64(baseAddress: Pointer, fieldOffset?: number): number {
-    return getValueU64((baseAddress as unknown as number) + (fieldOffset || 0));
-  },
-
-  readFloatField: function readHeapFloat(baseAddress: Pointer, fieldOffset?: number): number {
-    return getValueFloat((baseAddress as unknown as number) + (fieldOffset || 0));
+    return runtime.getHeapU52((baseAddress as any) + (fieldOffset || 0));
   },
 
-  readObjectField: function readHeapObject<T extends System_Object>(baseAddress: Pointer, fieldOffset?: number): T {
-    return getValueI32((baseAddress as unknown as number) + (fieldOffset || 0)) as any as T;
+  readObjectField: function readObjectField<T extends System_Object>(baseAddress: Pointer, fieldOffset?: number): T {
+    return runtime.getHeapU32((baseAddress as any) + (fieldOffset || 0)) as any as T;
   },
 
-  readStringField: function readHeapObject(baseAddress: Pointer, fieldOffset?: number, readBoolValueAsString?: boolean): string | null {
-    const fieldValue = getValueI32((baseAddress as unknown as number) + (fieldOffset || 0));
+  readStringField: function readStringField(baseAddress: Pointer, fieldOffset?: number, readBoolValueAsString?: boolean): string | null {
+    const fieldValue = runtime.getHeapU32((baseAddress as any) + (fieldOffset || 0));
     if (fieldValue === 0) {
       return null;
     }
@@ -129,14 +80,14 @@ export const monoPlatform: Platform = {
     if (readBoolValueAsString) {
       // Some fields are stored as a union of bool | string | null values, but need to read as a string.
       // If the stored value is a bool, the behavior we want is empty string ('') for true, or null for false.
-      const unboxedValue = BINDING.unbox_mono_obj(fieldValue as any as System_Object);
+
+      const unboxedValue = MONO_INTERNAL.monoObjectAsBoolOrNullUnsafe(fieldValue as any as System_Object);
       if (typeof (unboxedValue) === 'boolean') {
         return unboxedValue ? '' : null;
       }
-      return unboxedValue;
     }
 
-    return BINDING.conv_string(fieldValue as any as System_String);
+    return MONO_INTERNAL.monoStringToStringUnsafe(fieldValue as any as System_String);
   },
 
   readStructField: function readStructField<T extends Pointer>(baseAddress: Pointer, fieldOffset?: number): T {
@@ -206,13 +157,12 @@ function prepareRuntimeConfig(options: Partial<WebAssemblyStartOptions>, onConfi
     jsInitializer = await fetchAndInvokeInitializers(options, loadedConfig);
   };
 
-  const moduleConfig = (window['Module'] || {}) as typeof Module;
+  const moduleConfig = (window['Module'] || {}) as any;
   const dotnetModuleConfig: DotnetModuleConfig = {
     ...moduleConfig,
     onConfigLoaded: (onConfigLoaded as (config: MonoConfig) => void | Promise<void>),
     onDownloadResourceProgress: setProgress,
     config,
-    disableDotnet6Compatibility: false,
     out: print,
     err: printErr,
   };
@@ -251,10 +201,7 @@ async function configureRuntimeInstance(): Promise<PlatformApi> {
     throw new Error('The runtime must be loaded it gets configured.');
   }
 
-  const { MONO: mono, BINDING: binding, Module: module, setModuleImports, INTERNAL: mono_internal, getConfig, invokeLibraryInitializers } = runtime;
-  Module = module;
-  BINDING = binding;
-  MONO = mono;
+  const { setModuleImports, INTERNAL: mono_internal, getConfig, invokeLibraryInitializers } = runtime;
   MONO_INTERNAL = mono_internal;
 
   attachDebuggerHotkey(getConfig());
@@ -285,7 +232,7 @@ function setProgress(resourcesLoaded, totalResources) {
 
 const suppressMessages = ['DEBUGGING ENABLED'];
 const print = line => (suppressMessages.indexOf(line) < 0 && console.log(line));
-const printErr = line => {
+export const printErr = line => {
   // If anything writes to stderr, treat it as a critical exception. The underlying runtime writes
   // to stderr if a truly critical problem occurs outside .NET code. Note that .NET unhandled
   // exceptions also reach this, but via a different code path - see dotNetCriticalError below.
diff --git a/src/Components/Web.JS/src/Platform/Mono/MonoTypes.ts b/src/Components/Web.JS/src/Platform/Mono/MonoTypes.ts
deleted file mode 100644
index e7bf0e2e11ef..000000000000
--- a/src/Components/Web.JS/src/Platform/Mono/MonoTypes.ts
+++ /dev/null
@@ -1,34 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-import { Pointer, System_String, System_Array, System_Object } from '../Platform';
-
-// Mono uses this global to hang various debugging-related items on
-
-declare interface MONO {
-  loaded_files: string[];
-  mono_wasm_runtime_ready (): void;
-  mono_wasm_setenv (name: string, value: string): void;
-  mono_wasm_load_data_archive(data: Uint8Array, prefix: string): void;
-  mono_wasm_load_bytes_into_heap (data: Uint8Array): Pointer;
-  mono_wasm_load_icu_data(heapAddress: Pointer): boolean;
-}
-
-// Mono uses this global to hold low-level interop APIs
-declare interface BINDING {
-  mono_obj_array_new(length: number): System_Array<System_Object>;
-  mono_obj_array_set(array: System_Array<System_Object>, index: number, value: System_Object): void;
-  js_string_to_mono_string(jsString: string): System_String;
-  js_typed_array_to_array(array: Uint8Array): System_Object;
-  js_to_mono_obj(jsObject: unknown) : System_Object;
-  mono_array_to_js_array<TInput, TOutput>(array: System_Array<TInput>) : Array<TOutput>;
-  conv_string(dotnetString: System_String | null): string | null;
-  bind_static_method(fqn: string, signature?: string): Function;
-  call_assembly_entry_point(assemblyName: string, args: unknown[], signature: unknown): Promise<unknown>;
-  unbox_mono_obj(object: System_Object): unknown;
-}
-
-declare global {
-  let MONO: MONO;
-  let BINDING: BINDING;
-}
diff --git a/src/Components/Web.JS/src/Platform/Platform.ts b/src/Components/Web.JS/src/Platform/Platform.ts
index cb5de4c8c731..728bd330b33d 100644
--- a/src/Components/Web.JS/src/Platform/Platform.ts
+++ b/src/Components/Web.JS/src/Platform/Platform.ts
@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+/* eslint-disable @typescript-eslint/ban-types */
+/* eslint-disable @typescript-eslint/no-unused-vars */
 import { MonoObject, MonoString, MonoArray } from 'dotnet-runtime/dotnet-legacy';
 import { WebAssemblyStartOptions } from './WebAssemblyStartOptions';
 import { MonoConfig } from 'dotnet-runtime';
@@ -11,16 +13,12 @@ export interface Platform {
 
   callEntryPoint(): Promise<unknown>;
 
-  toUint8Array(array: System_Array<unknown>): Uint8Array;
-
-  getArrayLength(array: System_Array<unknown>): number;
   getArrayEntryPtr<TPtr extends Pointer>(array: System_Array<TPtr>, index: number, itemSize: number): TPtr;
 
   getObjectFieldsBaseAddress(referenceTypedObject: System_Object): Pointer;
   readInt16Field(baseAddress: Pointer, fieldOffset?: number): number;
   readInt32Field(baseAddress: Pointer, fieldOffset?: number): number;
   readUint64Field(baseAddress: Pointer, fieldOffset?: number): number;
-  readFloatField(baseAddress: Pointer, fieldOffset?: number): number;
   readObjectField<T extends System_Object>(baseAddress: Pointer, fieldOffset?: number): T;
   readStringField(baseAddress: Pointer, fieldOffset?: number, readBoolValueAsString?: boolean): string | null;
   readStructField<T extends Pointer>(baseAddress: Pointer, fieldOffset?: number): T;
diff --git a/src/Components/WebAssembly/JSInterop/src/PublicAPI.Unshipped.txt b/src/Components/WebAssembly/JSInterop/src/PublicAPI.Unshipped.txt
index 7dc5c58110bf..9f03b1a9685f 100644
--- a/src/Components/WebAssembly/JSInterop/src/PublicAPI.Unshipped.txt
+++ b/src/Components/WebAssembly/JSInterop/src/PublicAPI.Unshipped.txt
@@ -1 +1,9 @@
 #nullable enable
+*REMOVED*~Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2) -> TResult
+*REMOVED*~Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1) -> TResult
+*REMOVED*~Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0) -> TResult
+*REMOVED*~Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<TResult>(string identifier) -> TResult
+*REMOVED*Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<T0, T1, T2, TResult>(string! identifier, T0 arg0, T1 arg1, T2 arg2) -> TResult
+*REMOVED*Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<T0, T1, TResult>(string! identifier, T0 arg0, T1 arg1) -> TResult
+*REMOVED*Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<T0, TResult>(string! identifier, T0 arg0) -> TResult
+*REMOVED*Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled<TResult>(string! identifier) -> TResult
diff --git a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReference.cs b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReference.cs
index 1535be93b970..20027bd52474 100644
--- a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReference.cs
+++ b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReference.cs
@@ -5,7 +5,7 @@
 
 namespace Microsoft.JSInterop.WebAssembly;
 
-internal sealed class WebAssemblyJSObjectReference : JSInProcessObjectReference, IJSUnmarshalledObjectReference
+internal sealed class WebAssemblyJSObjectReference : JSInProcessObjectReference
 {
     private readonly WebAssemblyJSRuntime _jsRuntime;
 
@@ -14,38 +14,4 @@ public WebAssemblyJSObjectReference(WebAssemblyJSRuntime jsRuntime, long id)
     {
         _jsRuntime = jsRuntime;
     }
-
-#pragma warning disable CS0612 // Type or member is obsolete
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<TResult>(string identifier)
-    {
-        ThrowIfDisposed();
-
-        return _jsRuntime.InvokeUnmarshalled<object?, object?, object?, TResult>(identifier, null, null, null, Id);
-    }
-
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0)
-    {
-        ThrowIfDisposed();
-
-        return _jsRuntime.InvokeUnmarshalled<T0, object?, object?, TResult>(identifier, arg0, null, null, Id);
-    }
-
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1)
-    {
-        ThrowIfDisposed();
-
-        return _jsRuntime.InvokeUnmarshalled<T0, T1, object?, TResult>(identifier, arg0, arg1, null, Id);
-    }
-
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2)
-    {
-        ThrowIfDisposed();
-
-        return _jsRuntime.InvokeUnmarshalled<T0, T1, T2, TResult>(identifier, arg0, arg1, arg2, Id);
-    }
-#pragma warning restore CS0612 // Type or member is obsolete
 }
diff --git a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReferenceJsonConverter.cs b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReferenceJsonConverter.cs
index 32ae814a7efe..ff294cef2648 100644
--- a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReferenceJsonConverter.cs
+++ b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSObjectReferenceJsonConverter.cs
@@ -20,8 +20,7 @@ public override bool CanConvert(Type typeToConvert)
     {
         return typeToConvert == typeof(WebAssemblyJSObjectReference) ||
             typeToConvert == typeof(IJSObjectReference) ||
-            typeToConvert == typeof(IJSInProcessObjectReference) ||
-            typeToConvert == typeof(IJSUnmarshalledObjectReference);
+            typeToConvert == typeof(IJSInProcessObjectReference);
     }
 
     public override IJSObjectReference? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
diff --git a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
index 7edc56420263..21f62b89f369 100644
--- a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
+++ b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
@@ -12,7 +12,7 @@ namespace Microsoft.JSInterop.WebAssembly;
 /// Provides methods for invoking JavaScript functions for applications running
 /// on the Mono WebAssembly runtime.
 /// </summary>
-public abstract class WebAssemblyJSRuntime : JSInProcessRuntime, IJSUnmarshalledRuntime
+public abstract class WebAssemblyJSRuntime : JSInProcessRuntime
 {
     /// <summary>
     /// Initializes a new instance of <see cref="WebAssemblyJSRuntime"/>.
@@ -56,73 +56,4 @@ protected override void SendByteArray(int id, byte[] data)
     {
         InternalCalls.ReceiveByteArray(id, data);
     }
-
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    internal TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2, long targetInstanceId)
-    {
-        var resultType = JSCallResultTypeHelper.FromGeneric<TResult>();
-
-        var callInfo = new JSCallInfo
-        {
-            FunctionIdentifier = identifier,
-            TargetInstanceId = targetInstanceId,
-            ResultType = resultType,
-        };
-
-        string exception;
-
-        switch (resultType)
-        {
-            case JSCallResultType.Default:
-            case JSCallResultType.JSVoidResult:
-                var result = InternalCalls.InvokeJS<T0, T1, T2, TResult>(out exception, ref callInfo, arg0, arg1, arg2);
-                return exception != null
-                    ? throw new JSException(exception)
-                    : result;
-            case JSCallResultType.JSObjectReference:
-                var id = InternalCalls.InvokeJS<T0, T1, T2, int>(out exception, ref callInfo, arg0, arg1, arg2);
-                return exception != null
-                    ? throw new JSException(exception)
-                    : (TResult)(object)new WebAssemblyJSObjectReference(this, id);
-            case JSCallResultType.JSStreamReference:
-                var serializedStreamReference = InternalCalls.InvokeJS<T0, T1, T2, string>(out exception, ref callInfo, arg0, arg1, arg2);
-                return exception != null
-                    ? throw new JSException(exception)
-                    : (TResult)(object)DeserializeJSStreamReference(serializedStreamReference);
-            default:
-                throw new InvalidOperationException($"Invalid result type '{resultType}'.");
-        }
-    }
-
-    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode", Justification = "IJSStreamReference is referenced in Microsoft.JSInterop.Infrastructure.JSStreamReferenceJsonConverter")]
-    private IJSStreamReference DeserializeJSStreamReference(string serializedStreamReference)
-    {
-        var jsStreamReference = JsonSerializer.Deserialize<IJSStreamReference>(serializedStreamReference, JsonSerializerOptions);
-        if (jsStreamReference is null)
-        {
-            throw new ArgumentException($"Failed to parse as {nameof(IJSStreamReference)}.", nameof(serializedStreamReference));
-        }
-
-        return jsStreamReference;
-    }
-
-    /// <inheritdoc />
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<TResult>(string identifier)
-        => InvokeUnmarshalled<object?, object?, object?, TResult>(identifier, null, null, null, 0);
-
-    /// <inheritdoc />
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0)
-        => InvokeUnmarshalled<T0, object?, object?, TResult>(identifier, arg0, null, null, 0);
-
-    /// <inheritdoc />
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1)
-        => InvokeUnmarshalled<T0, T1, object?, TResult>(identifier, arg0, arg1, null, 0);
-
-    /// <inheritdoc />
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    public TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2)
-        => InvokeUnmarshalled<T0, T1, T2, TResult>(identifier, arg0, arg1, arg2, 0);
 }
diff --git a/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.WarningSuppressions.xml b/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.WarningSuppressions.xml
index b394263f6173..86af354e396a 100644
--- a/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.WarningSuppressions.xml
+++ b/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.WarningSuppressions.xml
@@ -13,12 +13,6 @@
       <property name="Scope">member</property>
       <property name="Target">M:Microsoft.AspNetCore.Components.RootComponentTypeCache.ResolveType(Microsoft.AspNetCore.Components.RootComponentTypeCache.Key,System.Reflection.Assembly[])</property>
     </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2026</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:Microsoft.AspNetCore.Components.WebAssembly.Hosting.WebAssemblyHostBuilder.InitializeRegisteredRootComponents(Microsoft.JSInterop.IJSUnmarshalledRuntime)</property>
-    </attribute>
     <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
       <argument>ILLink</argument>
       <argument>IL2026</argument>
@@ -43,11 +37,5 @@
       <property name="Scope">member</property>
       <property name="Target">M:Microsoft.Extensions.HotReload.HotReloadAgent.&lt;GetHandlerActions&gt;g__GetUpdateMethod|9_1(System.Type,System.String)</property>
     </attribute>
-    <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
-      <argument>ILLink</argument>
-      <argument>IL2072</argument>
-      <property name="Scope">member</property>
-      <property name="Target">M:Microsoft.AspNetCore.Components.WebAssembly.Hosting.WebAssemblyHostBuilder.InitializeRegisteredRootComponents(Microsoft.JSInterop.IJSUnmarshalledRuntime)</property>
-    </attribute>
   </assembly>
 </linker>
\ No newline at end of file
diff --git a/src/Components/WebAssembly/WebAssembly/test/JSObjectReferenceJsonConverterTest.cs b/src/Components/WebAssembly/WebAssembly/test/JSObjectReferenceJsonConverterTest.cs
index ca2e50bd9608..65aeb2acf662 100644
--- a/src/Components/WebAssembly/WebAssembly/test/JSObjectReferenceJsonConverterTest.cs
+++ b/src/Components/WebAssembly/WebAssembly/test/JSObjectReferenceJsonConverterTest.cs
@@ -44,18 +44,4 @@ public void Read_ReadsJson_IJSInProcessObjectReference()
         // Assert
         Assert.Equal(expectedId, deserialized?.Id);
     }
-
-    [Fact]
-    public void Read_ReadsJson_IJSUnmarshalledObjectReference()
-    {
-        // Arrange
-        var expectedId = 3;
-        var json = $"{{\"__jsObjectId\":{expectedId}}}";
-
-        // Act
-        var deserialized = (WebAssemblyJSObjectReference)JsonSerializer.Deserialize<IJSUnmarshalledObjectReference>(json, JsonSerializerOptions)!;
-
-        // Assert
-        Assert.Equal(expectedId, deserialized?.Id);
-    }
 }
diff --git a/src/Components/test/E2ETest/Tests/InteropTest.cs b/src/Components/test/E2ETest/Tests/InteropTest.cs
index bd233b4ffd5f..af5f69580065 100644
--- a/src/Components/test/E2ETest/Tests/InteropTest.cs
+++ b/src/Components/test/E2ETest/Tests/InteropTest.cs
@@ -133,9 +133,6 @@ public void CanInvokeDotNetMethods()
             ["invokeThrowsSerializingCircularStructure"] = "Success",
             ["invokeThrowsUndefinedJSObjectReference"] = "Success",
             ["invokeThrowsNullJSObjectReference"] = "Success",
-            ["jsUnmarshalledObjectReference.unmarshalledFunction"] = "True",
-            ["jsToDotNetStreamReturnValueUnmarshalled"] = "Success",
-            ["jsCastedUnmarshalledObjectReference.unmarshalledFunction"] = "False",
             ["stringValueUpperSync"] = "MY STRING",
             ["testDtoNonSerializedValueSync"] = "99999",
             ["testDtoSync"] = "Same",
@@ -144,7 +141,6 @@ public void CanInvokeDotNetMethods()
             ["genericInstanceMethod"] = @"""Updated value 2""",
             ["requestDotNetStreamReference"] = @"""Success""",
             ["requestDotNetStreamWrapperReference"] = @"""Success""",
-            ["disposeJSInProcessObjectReference"] = "Success",
         };
 
         // Include the sync assertions only when running under WebAssembly
diff --git a/src/Components/test/testassets/BasicTestApp/InteropComponent.razor b/src/Components/test/testassets/BasicTestApp/InteropComponent.razor
index 31d28fd23ffd..6310b0e745be 100644
--- a/src/Components/test/testassets/BasicTestApp/InteropComponent.razor
+++ b/src/Components/test/testassets/BasicTestApp/InteropComponent.razor
@@ -236,7 +236,7 @@
 
         if (shouldSupportSyncInterop)
         {
-            await InvokeInProcessJSInterop();
+            InvokeInProcessJSInterop();
         }
 
         var byteArray = new byte[] { 1, 5, 7, 15, 35, 200 };
@@ -334,7 +334,7 @@
         ReceiveDotNetObjectByRefResult["testDto"] = result.TestDto.Value == passDotNetObjectByRef ? "Same" : "Different";
     }
 
-    public async Task InvokeInProcessJSInterop()
+    public void InvokeInProcessJSInterop()
     {
         var inProcRuntime = ((IJSInProcessRuntime)JSRuntime);
 
@@ -408,39 +408,6 @@
         {
             ReturnValues["invokeVoidReturnsWithoutSerializingInIJSInProcessObjectReference"] = $"Failure: {ex.Message}";
         }
-
-        // we should be able to downcast a IJSInProcessObjectReference as a IJSUnmarshalledObjectReference
-        var unmarshalledCast = (IJSUnmarshalledObjectReference)jsInProcObjectReference;
-#pragma warning disable CS0618 // Type or member is obsolete
-        ReturnValues["jsCastedUnmarshalledObjectReference.unmarshalledFunction"] = unmarshalledCast.InvokeUnmarshalled<InteropStruct, bool>("unmarshalledFunction", new InteropStruct
-        {
-            Message = "Sent from .NET",
-            NumberField = 41,
-        }).ToString();
-
-        try
-        {
-            jsInProcObjectReference.Dispose();
-            ReturnValues["disposeJSInProcessObjectReference"] = "Success";
-        }
-        catch (Exception ex)
-        {
-            ReturnValues["disposeJSInProcessObjectReference"] = $"Failure: {ex.Message}";
-        }
-
-        var unmarshalledRuntime = (IJSUnmarshalledRuntime)JSRuntime;
-        var jsUnmarshalledReference = unmarshalledRuntime.InvokeUnmarshalled<IJSUnmarshalledObjectReference>("returnJSObjectReference");
-        ReturnValues["jsUnmarshalledObjectReference.unmarshalledFunction"] = jsUnmarshalledReference.InvokeUnmarshalled<InteropStruct, bool>("unmarshalledFunction", new InteropStruct
-        {
-            Message = "Sent from .NET",
-            NumberField = 42,
-        }).ToString();
-
-
-        var dataReference = unmarshalledRuntime.InvokeUnmarshalled<IJSStreamReference>("jsToDotNetStreamReturnValue");
-#pragma warning restore CS0618 // Type or member is obsolete
-        using var dataReferenceStream = await dataReference.OpenReadStreamAsync();
-        await ValidateStreamValuesAsync("jsToDotNetStreamReturnValueUnmarshalled", dataReferenceStream);
     }
 
     public class PassDotNetObjectByRefArgs
diff --git a/src/Components/test/testassets/BasicTestApp/wwwroot/js/jsinteroptests.js b/src/Components/test/testassets/BasicTestApp/wwwroot/js/jsinteroptests.js
index 8e344b4141b0..dac70d67e6ec 100644
--- a/src/Components/test/testassets/BasicTestApp/wwwroot/js/jsinteroptests.js
+++ b/src/Components/test/testassets/BasicTestApp/wwwroot/js/jsinteroptests.js
@@ -346,11 +346,6 @@ function returnJSObjectReference() {
     dispose: function () {
       DotNet.disposeJSObjectReference(this);
     },
-    unmarshalledFunction: function (fields) {
-      const message = Blazor.platform.readStringField(fields, 0);
-      const numberField = Blazor.platform.readInt32Field(fields, 8);
-      return message === "Sent from .NET" && numberField === 42;
-    }
   };
 }
 
diff --git a/src/JSInterop/Microsoft.JSInterop/src/IJSUnmarshalledObjectReference.cs b/src/JSInterop/Microsoft.JSInterop/src/IJSUnmarshalledObjectReference.cs
deleted file mode 100644
index e906556b0013..000000000000
--- a/src/JSInterop/Microsoft.JSInterop/src/IJSUnmarshalledObjectReference.cs
+++ /dev/null
@@ -1,58 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-namespace Microsoft.JSInterop;
-
-/// <summary>
-/// Represents a reference to a JavaScript object whose functions can be invoked synchronously without JSON marshalling.
-/// </summary>
-public interface IJSUnmarshalledObjectReference : IJSInProcessObjectReference
-{
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<TResult>(string identifier);
-
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="T0">The type of the first argument.</typeparam>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <param name="arg0">The first argument.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0);
-
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="T0">The type of the first argument.</typeparam>
-    /// <typeparam name="T1">The type of the second argument.</typeparam>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <param name="arg0">The first argument.</param>
-    /// <param name="arg1">The second argument.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1);
-
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="T0">The type of the first argument.</typeparam>
-    /// <typeparam name="T1">The type of the second argument.</typeparam>
-    /// <typeparam name="T2">The type of the third argument.</typeparam>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <param name="arg0">The first argument.</param>
-    /// <param name="arg1">The second argument.</param>
-    /// <param name="arg2">The third argument.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2);
-}
diff --git a/src/JSInterop/Microsoft.JSInterop/src/IJSUnmarshalledRuntime.cs b/src/JSInterop/Microsoft.JSInterop/src/IJSUnmarshalledRuntime.cs
deleted file mode 100644
index d5241f139258..000000000000
--- a/src/JSInterop/Microsoft.JSInterop/src/IJSUnmarshalledRuntime.cs
+++ /dev/null
@@ -1,61 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-namespace Microsoft.JSInterop;
-
-/// <summary>
-/// Represents an instance of a JavaScript runtime to which calls may be dispatched without JSON marshalling.
-/// Not all JavaScript runtimes support this capability. Currently it is only supported on WebAssembly and for
-/// security reasons, will never be supported for .NET code that runs on the server.
-/// This is an advanced mechanism that should only be used in performance-critical scenarios.
-/// </summary>
-public interface IJSUnmarshalledRuntime
-{
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<TResult>(string identifier);
-
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="T0">The type of the first argument.</typeparam>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <param name="arg0">The first argument.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0);
-
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="T0">The type of the first argument.</typeparam>
-    /// <typeparam name="T1">The type of the second argument.</typeparam>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <param name="arg0">The first argument.</param>
-    /// <param name="arg1">The second argument.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1);
-
-    /// <summary>
-    /// Invokes the JavaScript function registered with the specified identifier.
-    /// </summary>
-    /// <typeparam name="T0">The type of the first argument.</typeparam>
-    /// <typeparam name="T1">The type of the second argument.</typeparam>
-    /// <typeparam name="T2">The type of the third argument.</typeparam>
-    /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-    /// <param name="identifier">The identifier used when registering the target function.</param>
-    /// <param name="arg0">The first argument.</param>
-    /// <param name="arg1">The second argument.</param>
-    /// <param name="arg2">The third argument.</param>
-    /// <returns>The result of the function invocation.</returns>
-    [Obsolete("This method is obsolete. Use JSImportAttribute instead.")]
-    TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2);
-}
diff --git a/src/JSInterop/Microsoft.JSInterop/src/PublicAPI.Unshipped.txt b/src/JSInterop/Microsoft.JSInterop/src/PublicAPI.Unshipped.txt
index 7dc5c58110bf..d7a3755ff3c5 100644
--- a/src/JSInterop/Microsoft.JSInterop/src/PublicAPI.Unshipped.txt
+++ b/src/JSInterop/Microsoft.JSInterop/src/PublicAPI.Unshipped.txt
@@ -1 +1,11 @@
 #nullable enable
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledObjectReference
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledObjectReference.InvokeUnmarshalled<T0, T1, T2, TResult>(string! identifier, T0 arg0, T1 arg1, T2 arg2) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledObjectReference.InvokeUnmarshalled<T0, T1, TResult>(string! identifier, T0 arg0, T1 arg1) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledObjectReference.InvokeUnmarshalled<T0, TResult>(string! identifier, T0 arg0) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledObjectReference.InvokeUnmarshalled<TResult>(string! identifier) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledRuntime
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledRuntime.InvokeUnmarshalled<T0, T1, T2, TResult>(string! identifier, T0 arg0, T1 arg1, T2 arg2) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledRuntime.InvokeUnmarshalled<T0, T1, TResult>(string! identifier, T0 arg0, T1 arg1) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledRuntime.InvokeUnmarshalled<T0, TResult>(string! identifier, T0 arg0) -> TResult
+*REMOVED*Microsoft.JSInterop.IJSUnmarshalledRuntime.InvokeUnmarshalled<TResult>(string! identifier) -> TResult
\ No newline at end of file
diff --git a/src/JSInterop/Microsoft.JSInterop/test/Infrastructure/JSObjectReferenceJsonConverterTest.cs b/src/JSInterop/Microsoft.JSInterop/test/Infrastructure/JSObjectReferenceJsonConverterTest.cs
index ea82e11f0090..63b5a889782a 100644
--- a/src/JSInterop/Microsoft.JSInterop/test/Infrastructure/JSObjectReferenceJsonConverterTest.cs
+++ b/src/JSInterop/Microsoft.JSInterop/test/Infrastructure/JSObjectReferenceJsonConverterTest.cs
@@ -87,31 +87,4 @@ public void Write_WritesValidJson()
         // Assert
         Assert.Equal($"{{\"__jsObjectId\":{jsObjectRef.Id}}}", json);
     }
-
-    private class TestJSUnmarshalledObjectReference : JSInProcessObjectReference, IJSUnmarshalledObjectReference
-    {
-        public TestJSUnmarshalledObjectReference(long id) : base(default!, id)
-        {
-        }
-
-        public TResult InvokeUnmarshalled<TResult>(string identifier)
-        {
-            throw new NotImplementedException();
-        }
-
-        public TResult InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0)
-        {
-            throw new NotImplementedException();
-        }
-
-        public TResult InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1)
-        {
-            throw new NotImplementedException();
-        }
-
-        public TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2)
-        {
-            throw new NotImplementedException();
-        }
-    }
 }
diff --git a/src/Shared/JSInterop/JSCallResultTypeHelper.cs b/src/Shared/JSInterop/JSCallResultTypeHelper.cs
index 789f432de504..69e90b8943c2 100644
--- a/src/Shared/JSInterop/JSCallResultTypeHelper.cs
+++ b/src/Shared/JSInterop/JSCallResultTypeHelper.cs
@@ -16,8 +16,7 @@ public static JSCallResultType FromGeneric<TResult>()
         if (typeof(TResult).Assembly == _currentAssembly)
         {
             if (typeof(TResult) == typeof(IJSObjectReference) ||
-                typeof(TResult) == typeof(IJSInProcessObjectReference) ||
-                typeof(TResult) == typeof(IJSUnmarshalledObjectReference))
+                typeof(TResult) == typeof(IJSInProcessObjectReference))
             {
                 return JSCallResultType.JSObjectReference;
             }