diff --git a/__tests__/context.test.ts b/__tests__/context.test.ts
index da67084..f91af93 100644
--- a/__tests__/context.test.ts
+++ b/__tests__/context.test.ts
@@ -168,3 +168,23 @@ test('getAuthList masks registry-auth password when present', async () => {
 
   expect(stdoutWriteSpy.mock.calls.map(call => call[0]).join('')).toContain('::add-mask::groundcontrol');
 });
+
+// prettier-ignore
+test.each([
+  ['false', 'false'],
+  ['"false"', 'false'],
+  ['true', 'true'],
+  ['auto', 'auto'],
+  ['""', 'auto']
+])('getAuthList keeps registry-auth ecr: %s', async (ecr, expected) => {
+  const [auth] = getAuthList({
+    registry: '',
+    username: '',
+    password: '',
+    scope: '',
+    ecr: '',
+    logout: true,
+    registryAuth: `- registry: 012345678910.dkr.ecr.eu-west-3.amazonaws.com\n  username: AWS\n  password: token\n  ecr: ${ecr}\n`
+  });
+  expect(auth.ecr).toBe(expected);
+});
diff --git a/__tests__/docker.test.ts b/__tests__/docker.test.ts
index 4ad2d90..8df7e77 100644
--- a/__tests__/docker.test.ts
+++ b/__tests__/docker.test.ts
@@ -2,6 +2,8 @@ import {afterEach, expect, test, vi} from 'vitest';
 
 import {Docker} from '@docker/actions-toolkit/lib/docker/docker.js';
 
+import * as aws from '../src/aws.js';
+import {getAuthList} from '../src/context.js';
 import {login, loginStandard, logout} from '../src/docker.js';
 import * as dockerhub from '../src/dockerhub.js';
 
@@ -92,3 +94,30 @@ test('logout calls exec', async () => {
     ignoreReturnCode: true
   });
 });
+
+test('login uses standard login for an ECR registry with registry-auth ecr: false', async () => {
+  const execSpy = vi.spyOn(Docker, 'getExecOutput').mockResolvedValue({
+    exitCode: 0,
+    stdout: '',
+    stderr: ''
+  });
+  const ecrSpy = vi.spyOn(aws, 'getRegistriesData').mockRejectedValue(new Error('AWS SDK called'));
+
+  const [auth] = getAuthList({
+    registry: '',
+    username: '',
+    password: '',
+    scope: '',
+    ecr: '',
+    logout: true,
+    registryAuth: '- registry: 012345678910.dkr.ecr.eu-west-3.amazonaws.com\n  username: AWS\n  password: token\n  ecr: false\n'
+  });
+  await login(auth);
+
+  expect(ecrSpy).not.toHaveBeenCalled();
+  expect(execSpy).toHaveBeenCalledWith(['login', '--password-stdin', '--username', 'AWS', '012345678910.dkr.ecr.eu-west-3.amazonaws.com'], {
+    input: Buffer.from('token'),
+    silent: true,
+    ignoreReturnCode: true
+  });
+});
diff --git a/src/context.ts b/src/context.ts
index ba09b8b..e03973b 100644
--- a/src/context.ts
+++ b/src/context.ts
@@ -62,7 +62,8 @@ export function getAuthList(inputs: Inputs): Array<Auth> {
         username: auth.username,
         password: auth.password,
         scope: auth.scope,
-        ecr: auth.ecr || 'auto',
+        // YAML parses an unquoted `ecr: false` as a boolean, keep it instead of falling back to auto
+        ecr: String(auth.ecr ?? '') || 'auto',
         configDir: scopeToConfigDir(registry, auth.scope)
       };
     });