diff --git a/addons/auth/package.json b/addons/auth/package.json
index 6027059c8..f81b55c10 100644
--- a/addons/auth/package.json
+++ b/addons/auth/package.json
@@ -35,7 +35,6 @@
     "@glimmer/component": "^1.1.2",
     "@glimmer/tracking": "^1.1.2",
     "broccoli-asset-rev": "^3.0.0",
-    "core": "*",
     "doctoc": "^2.2.0",
     "ember-cli": "^4.4.0",
     "ember-cli-dependency-checker": "^3.2.0",
@@ -59,6 +58,7 @@
     "eslint-plugin-qunit": "^7.3.0",
     "loader.js": "^4.7.0",
     "npm-run-all": "^4.1.5",
+    "pretender": "^3.4.3",
     "prettier": "^2.4.0",
     "qunit": "^2.17.1",
     "qunit-dom": "^2.0.0",
diff --git a/addons/auth/tests/unit/authenticators/base-test.js b/addons/auth/tests/unit/authenticators/base-test.js
index c79f21be9..d9a8145dd 100644
--- a/addons/auth/tests/unit/authenticators/base-test.js
+++ b/addons/auth/tests/unit/authenticators/base-test.js
@@ -1,19 +1,27 @@
 import { module, test } from 'qunit';
 import { setupTest } from 'ember-qunit';
-import { Response } from 'miragejs';
-import setupMirage from 'ember-cli-mirage/test-support/setup-mirage';
+import Pretender from 'pretender';
 
 module('Unit | Authenticator | base', function (hooks) {
   setupTest(hooks);
-  setupMirage(hooks);
+
+  let server;
+
+  hooks.beforeEach(() => {
+    server = new Pretender();
+  });
+
+  hooks.afterEach(() => {
+    server.shutdown();
+  });
 
   test('it deauthenticates on invalidation', async function (assert) {
     assert.expect(1);
     const authenticator = this.owner.lookup('authenticator:base');
     const endpoint = authenticator.buildDeauthEndpointURL({ id: 'token123' });
-    this.server.delete(endpoint, () => {
+    server.delete(endpoint, () => {
       assert.ok(true, 'deauthentication occurred');
-      return new Response(200);
+      return [200];
     });
     await authenticator.invalidate({ token: 'token123' });
   });
@@ -22,9 +30,9 @@ module('Unit | Authenticator | base', function (hooks) {
     assert.expect(2);
     const authenticator = this.owner.lookup('authenticator:base');
     const endpoint = authenticator.buildDeauthEndpointURL({ id: 'token123' });
-    this.server.delete(endpoint, () => {
+    server.delete(endpoint, () => {
       assert.ok(true, 'deauthentication was requested');
-      return new Response(500);
+      return [500];
     });
     await authenticator
       .invalidate({ token: 'token123' })
@@ -37,9 +45,9 @@ module('Unit | Authenticator | base', function (hooks) {
     const id = 'token_123';
     const mockData = { attributes: { id } };
     const authenticator = this.owner.lookup('authenticator:base');
-    this.server.get(authenticator.buildTokenValidationEndpointURL(id), () => {
+    server.get(authenticator.buildTokenValidationEndpointURL(id), () => {
       assert.ok(true, 'token validation was requested');
-      return new Response(200);
+      return [200];
     });
     await authenticator.restore(mockData);
   });
@@ -49,9 +57,9 @@ module('Unit | Authenticator | base', function (hooks) {
     const id = 'token_123';
     const mockData = { attributes: { id } };
     const authenticator = this.owner.lookup('authenticator:base');
-    this.server.get(authenticator.buildTokenValidationEndpointURL(id), () => {
+    server.get(authenticator.buildTokenValidationEndpointURL(id), () => {
       assert.ok(true, 'token validation was requested');
-      return new Response(401);
+      return [401];
     });
     try {
       await authenticator.restore(mockData);
@@ -65,9 +73,9 @@ module('Unit | Authenticator | base', function (hooks) {
     const id = 'token_123';
     const mockData = { attributes: { id } };
     const authenticator = this.owner.lookup('authenticator:base');
-    this.server.get(authenticator.buildTokenValidationEndpointURL(id), () => {
+    server.get(authenticator.buildTokenValidationEndpointURL(id), () => {
       assert.ok(true, 'token validation was requested');
-      return new Response(404);
+      return [404];
     });
     try {
       await authenticator.restore(mockData);
diff --git a/addons/auth/tests/unit/authenticators/oidc-test.js b/addons/auth/tests/unit/authenticators/oidc-test.js
index e2e7bb0a9..f059b32fe 100644
--- a/addons/auth/tests/unit/authenticators/oidc-test.js
+++ b/addons/auth/tests/unit/authenticators/oidc-test.js
@@ -1,19 +1,28 @@
 import { module, test } from 'qunit';
 import { setupTest } from 'ember-qunit';
-import { Response } from 'miragejs';
-import setupMirage from 'ember-cli-mirage/test-support/setup-mirage';
+import Pretender from 'pretender';
 
 module('Unit | Authenticator | OIDC', function (hooks) {
   setupTest(hooks);
-  setupMirage(hooks);
+
+  let server;
+
+  hooks.beforeEach(() => {
+    server = new Pretender();
+  });
+
+  hooks.afterEach(() => {
+    server.shutdown();
+  });
 
   test('`startAuthentication` initiates the authentication flow and returns the response', async function (assert) {
     assert.expect(2);
     const authenticator = this.owner.lookup('authenticator:oidc');
-    this.server.post(
-      authenticator.buildAuthEndpointURL(),
-      () => new Response(200, {}, { foo: 'bar' })
-    );
+    server.post(authenticator.buildAuthEndpointURL(), () => [
+      200,
+      {},
+      JSON.stringify({ foo: 'bar' }),
+    ]);
     const response = await authenticator.startAuthentication();
     assert.ok(true, 'authentication succeeded');
     assert.deepEqual(response, { foo: 'bar' });
@@ -22,10 +31,7 @@ module('Unit | Authenticator | OIDC', function (hooks) {
   test('`startAuthentication` rejects/errors if API returns an error response', async function (assert) {
     assert.expect(1);
     const authenticator = this.owner.lookup('authenticator:oidc');
-    this.server.post(
-      authenticator.buildAuthEndpointURL(),
-      () => new Response(400)
-    );
+    server.post(authenticator.buildAuthEndpointURL(), () => [400]);
     // Because assert.throws doesn't work with async errors/promise rejections
     try {
       await authenticator.startAuthentication();
diff --git a/addons/auth/tests/unit/authenticators/password-test.js b/addons/auth/tests/unit/authenticators/password-test.js
index ac036d9ab..5838194a2 100644
--- a/addons/auth/tests/unit/authenticators/password-test.js
+++ b/addons/auth/tests/unit/authenticators/password-test.js
@@ -1,23 +1,28 @@
 import { module, test } from 'qunit';
 import { setupTest } from 'ember-qunit';
-import { Response } from 'miragejs';
-import setupMirage from 'ember-cli-mirage/test-support/setup-mirage';
+import Pretender from 'pretender';
 
 module('Unit | Authenticator | password', function (hooks) {
   setupTest(hooks);
-  setupMirage(hooks);
+
+  let server;
+
+  hooks.beforeEach(() => {
+    server = new Pretender();
+  });
+
+  hooks.afterEach(() => {
+    server.shutdown();
+  });
 
   test('it authenticates to the specified authEndpoint', async function (assert) {
     assert.expect(2);
     const authenticator = this.owner.lookup('authenticator:password');
-    this.server.post(
-      authenticator.buildAuthEndpointURL(),
-      (schema, request) => {
-        const json = JSON.parse(request.requestBody);
-        assert.ok(json.type, 'Requested token cookies by default');
-        return new Response(200);
-      }
-    );
+    server.post(authenticator.buildAuthEndpointURL(), (request) => {
+      const json = JSON.parse(request.requestBody);
+      assert.ok(json.type, 'Requested token cookies by default');
+      return [200, {}, '{}'];
+    });
     await authenticator.authenticate({}).then(() => {
       assert.ok(true, 'authentication succeeded');
     });
@@ -26,14 +31,11 @@ module('Unit | Authenticator | password', function (hooks) {
   test('it can authenticate without requesting cookies', async function (assert) {
     assert.expect(2);
     const authenticator = this.owner.lookup('authenticator:password');
-    this.server.post(
-      authenticator.buildAuthEndpointURL(),
-      (schema, request) => {
-        const json = JSON.parse(request.requestBody);
-        assert.notOk(json.type, 'Did not request tokens cookies');
-        return new Response(200);
-      }
-    );
+    server.post(authenticator.buildAuthEndpointURL(), (request) => {
+      const json = JSON.parse(request.requestBody);
+      assert.notOk(json.type, 'Did not request tokens cookies');
+      return [200, {}, '{}'];
+    });
     await authenticator.authenticate({}, false).then(() => {
       assert.ok(true, 'authentication succeeded');
     });
@@ -42,21 +44,18 @@ module('Unit | Authenticator | password', function (hooks) {
   test('it authenticates with the expected payload', async function (assert) {
     assert.expect(1);
     const authenticator = this.owner.lookup('authenticator:password');
-    this.server.post(
-      authenticator.buildAuthEndpointURL(),
-      (schema, request) => {
-        const json = JSON.parse(request.requestBody);
-        assert.deepEqual(json, {
-          command: 'login',
-          type: 'cookie',
-          attributes: {
-            login_name: 'foo',
-            password: 'bar',
-          },
-        });
-        return new Response(200);
-      }
-    );
+    server.post(authenticator.buildAuthEndpointURL(), (request) => {
+      const json = JSON.parse(request.requestBody);
+      assert.deepEqual(json, {
+        command: 'login',
+        type: 'cookie',
+        attributes: {
+          login_name: 'foo',
+          password: 'bar',
+        },
+      });
+      return [200, {}, '{}'];
+    });
     const creds = {
       identification: 'foo',
       password: 'bar',
@@ -67,8 +66,8 @@ module('Unit | Authenticator | password', function (hooks) {
   test('it rejects if the endpoint sends an error status code', async function (assert) {
     assert.expect(1);
     const authenticator = this.owner.lookup('authenticator:password');
-    this.server.post(authenticator.buildAuthEndpointURL(), () => {
-      return new Response(400);
+    server.post(authenticator.buildAuthEndpointURL(), () => {
+      return [400];
     });
     await authenticator.authenticate({}).catch(() => {
       assert.ok(true, 'authentication failed');