diff --git a/packages/ai/src/auth/oauth/aimlapi.ts b/packages/ai/src/auth/oauth/aimlapi.ts
index d2611f95bf7..b3f0c5d76e8 100644
--- a/packages/ai/src/auth/oauth/aimlapi.ts
+++ b/packages/ai/src/auth/oauth/aimlapi.ts
@@ -132,11 +132,9 @@ async function loginAimlapi(interaction: ProviderAuthInteraction): Promise<OAuth
 		);
 	}
 
-	if (account.provider) {
-		throw new Error(
-			`This email signs in via ${account.provider} on AI/ML API — sign in at https://aimlapi.com/app and create an API key manually instead.`,
-		);
-	}
+	// A correct emailed code proves ownership regardless of how the account was
+	// originally created — sign-in/code/verify has no dependency on a linked
+	// OAuth provider (e.g. Google), so this path works even for those accounts.
 	await sendSignInCode(email, interaction.signal);
 	interaction.notify({ type: "info", message: `A 6-digit code was sent to ${email}.` });
 	const rawCode = await interaction.prompt({ type: "text", message: "Enter the 6-digit code" });
diff --git a/packages/ai/test/aimlapi-oauth.test.ts b/packages/ai/test/aimlapi-oauth.test.ts
index 60c2ac38aef..07d7d02906b 100644
--- a/packages/ai/test/aimlapi-oauth.test.ts
+++ b/packages/ai/test/aimlapi-oauth.test.ts
@@ -94,19 +94,27 @@ describe.sequential("AI/ML API OAuth", () => {
 		expect(calls).toEqual([ACCOUNT_URL, PASSWORDLESS_URL]);
 	});
 
-	it("rejects an account linked to a third-party sign-in provider", async () => {
+	it("signs in an account linked to a third-party provider through the same emailed code — sign-in/code/verify has no provider dependency", async () => {
 		vi.stubGlobal(
 			"fetch",
-			vi.fn(async () => jsonResponse({ action: "sign-in", provider: "google" })),
+			vi.fn(async (input: string | URL | Request) => {
+				const url = input instanceof Request ? input.url : String(input);
+				if (url === ACCOUNT_URL) return jsonResponse({ action: "sign-in", provider: "google" });
+				if (url === SEND_CODE_URL) return new Response(null, { status: 204 });
+				if (url === VERIFY_CODE_URL) return jsonResponse({ token: "session-token", exp: 9999999999 });
+				if (url === KEYS_URL) return jsonResponse({ key: "aiml-google-key", id: "key-3" });
+				throw new Error(`Unexpected request: ${url}`);
+			}),
 		);
 
-		await expect(
-			aimlapiOAuth.login({
-				signal: neverAbortedSignal,
-				prompt: async () => "user@example.com",
-				notify: () => {},
-			}),
-		).rejects.toThrow(/signs in via google/);
+		const prompts = ["user@example.com", "123456"];
+		const credential = await aimlapiOAuth.login({
+			signal: neverAbortedSignal,
+			prompt: async () => prompts.shift() ?? "",
+			notify: () => {},
+		});
+
+		expect(credential).toMatchObject({ access: "aiml-google-key" });
 	});
 
 	it("reports an invalid verification code", async () => {