diff --git a/packages/@ember/-internals/glimmer/lib/utils/managers.ts b/packages/@ember/-internals/glimmer/lib/utils/managers.ts
index c12bf49ba41..0073b4e1991 100644
--- a/packages/@ember/-internals/glimmer/lib/utils/managers.ts
+++ b/packages/@ember/-internals/glimmer/lib/utils/managers.ts
@@ -1,6 +1,5 @@
 import { Owner } from '@ember/-internals/owner';
 import { deprecate } from '@ember/debug';
-import { COMPONENT_MANAGER_STRING_LOOKUP } from '@ember/deprecated-features';
 import { DEBUG } from '@glimmer/env';
 import { ComponentManager } from '@glimmer/interfaces';
 import {
@@ -10,33 +9,10 @@ import {
 } from '@glimmer/manager';
 
 export function setComponentManager(
-  stringOrFunction: string | ((owner: Owner) => ComponentManager<unknown>),
+  manager: (owner: Owner) => ComponentManager<unknown>,
   obj: object
 ): object {
-  let factory: (owner: Owner) => ComponentManager<unknown>;
-
-  if (COMPONENT_MANAGER_STRING_LOOKUP && typeof stringOrFunction === 'string') {
-    deprecate(
-      'Passing the name of the component manager to "setupComponentManager" is deprecated. Please pass a function that produces an instance of the manager.',
-      false,
-      {
-        id: 'deprecate-string-based-component-manager',
-        until: '4.0.0',
-        url: 'https://deprecations.emberjs.com/v3.x/#toc_component-manager-string-lookup',
-        for: 'ember-source',
-        since: {
-          enabled: '3.8.0',
-        },
-      }
-    );
-    factory = function (owner: Owner) {
-      return owner.lookup<ComponentManager<unknown>>(`component-manager:${stringOrFunction}`)!;
-    };
-  } else {
-    factory = stringOrFunction as (owner: Owner) => ComponentManager<unknown>;
-  }
-
-  return glimmerSetComponentManager(factory, obj);
+  return glimmerSetComponentManager(manager, obj);
 }
 
 export let componentCapabilities = glimmerComponentCapabilities;
diff --git a/packages/@ember/-internals/glimmer/tests/integration/custom-component-manager-test.js b/packages/@ember/-internals/glimmer/tests/integration/custom-component-manager-test.js
index 24b6cfe7ee4..21b94917b80 100644
--- a/packages/@ember/-internals/glimmer/tests/integration/custom-component-manager-test.js
+++ b/packages/@ember/-internals/glimmer/tests/integration/custom-component-manager-test.js
@@ -80,17 +80,6 @@ class ComponentManagerTest extends RenderingTestCase {
 moduleFor(
   'Component Manager - Curly Invocation',
   class extends ComponentManagerTest {
-    ['@test the string based version of setComponentManager is deprecated']() {
-      expectDeprecation(() => {
-        setComponentManager(
-          'basic',
-          EmberObject.extend({
-            greeting: 'hello',
-          })
-        );
-      }, 'Passing the name of the component manager to "setupComponentManager" is deprecated. Please pass a function that produces an instance of the manager.');
-    }
-
     ['@test it can render a basic component with custom component manager']() {
       let ComponentClass = setComponentManager(
         createBasicManager,
diff --git a/packages/@ember/deprecated-features/index.ts b/packages/@ember/deprecated-features/index.ts
index 67122f2e569..120076be816 100644
--- a/packages/@ember/deprecated-features/index.ts
+++ b/packages/@ember/deprecated-features/index.ts
@@ -6,7 +6,6 @@
 export const SEND_ACTION = !!'3.4.0';
 export const EMBER_EXTEND_PROTOTYPES = !!'3.2.0-beta.5';
 export const ROUTER_EVENTS = !!'4.0.0';
-export const COMPONENT_MANAGER_STRING_LOOKUP = !!'3.8.0';
 export const JQUERY_INTEGRATION = !!'3.9.0';
 export const APP_CTRL_ROUTER_PROPS = !!'3.10.0-beta.1';
 export const FUNCTION_PROTOTYPE_EXTENSIONS = !!'3.11.0-beta.1';