diff --git a/src/commands/auth-choice.apply.ts b/src/commands/auth-choice.apply.ts
index a330d364e55..1674b30ba92 100644
--- a/src/commands/auth-choice.apply.ts
+++ b/src/commands/auth-choice.apply.ts
@@ -42,6 +42,25 @@ async function normalizeTokenProviderChoice(params: {
   });
 }
 
+async function formatDeprecatedProviderChoiceError(
+  authChoice: AuthChoice | undefined,
+  params: Pick<ApplyAuthChoiceParams, "config" | "env">,
+): Promise<string | undefined> {
+  if (typeof authChoice !== "string") {
+    return undefined;
+  }
+  const { resolveManifestDeprecatedProviderAuthChoice } =
+    await import("../plugins/provider-auth-choices.js");
+  const deprecatedChoice = resolveManifestDeprecatedProviderAuthChoice(authChoice, {
+    config: params.config,
+    env: params.env,
+  });
+  if (!deprecatedChoice) {
+    return undefined;
+  }
+  return `Auth choice "${authChoice}" is no longer supported. Use "${deprecatedChoice.choiceId}" instead.`;
+}
+
 export async function applyAuthChoice(
   params: ApplyAuthChoiceParams,
 ): Promise<ApplyAuthChoiceResult> {
@@ -63,6 +82,17 @@ export async function applyAuthChoice(
     return result;
   }
 
+  const deprecatedProviderChoiceError = await formatDeprecatedProviderChoiceError(
+    normalizedParams.authChoice,
+    {
+      config: normalizedParams.config,
+      env: normalizedParams.env,
+    },
+  );
+  if (deprecatedProviderChoiceError) {
+    throw new Error(deprecatedProviderChoiceError);
+  }
+
   if (normalizedParams.authChoice === "token" || normalizedParams.authChoice === "setup-token") {
     throw new Error(
       [
diff --git a/src/commands/auth-choice.test.ts b/src/commands/auth-choice.test.ts
index d2fce6de550..f8305b5ffce 100644
--- a/src/commands/auth-choice.test.ts
+++ b/src/commands/auth-choice.test.ts
@@ -691,6 +691,20 @@ describe("applyAuthChoice", () => {
     );
   });
 
+  it("fails fast when a removed provider auth choice is passed to the interactive flow", async () => {
+    await expect(
+      applyAuthChoice({
+        authChoice: "openai-codex-import",
+        config: {},
+        prompter: createPrompter({}),
+        runtime: createExitThrowingRuntime(),
+        setDefaultModel: true,
+      }),
+    ).rejects.toThrow(
+      'Auth choice "openai-codex-import" is no longer supported. Use "openai-codex" instead.',
+    );
+  });
+
   it("prompts and writes provider API key profiles for common providers", async () => {
     const scenarios: Array<{
       authChoice: "huggingface-api-key";