diff --git a/packages/ai/CHANGELOG.md b/packages/ai/CHANGELOG.md
index 151283077..cfdf9a3e0 100644
--- a/packages/ai/CHANGELOG.md
+++ b/packages/ai/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed Anthropic and Bedrock adaptive-thinking payload tests to expect the default `display: "summarized"` field when reasoning is enabled.
+
 ## [0.67.6] - 2026-04-16
 
 ### Added
diff --git a/packages/ai/test/anthropic-thinking-disable.test.ts b/packages/ai/test/anthropic-thinking-disable.test.ts
index 7f406b30f..8f871514c 100644
--- a/packages/ai/test/anthropic-thinking-disable.test.ts
+++ b/packages/ai/test/anthropic-thinking-disable.test.ts
@@ -4,7 +4,7 @@ import { streamSimple } from "../src/stream.js";
 import type { Context, Model, SimpleStreamOptions } from "../src/types.js";
 
 interface AnthropicThinkingPayload {
-	thinking?: { type: string; budget_tokens?: number };
+	thinking?: { type: string; budget_tokens?: number; display?: string };
 	output_config?: { effort?: string };
 }
 
@@ -128,14 +128,14 @@ describe("Anthropic thinking disable payload", () => {
 	it("uses adaptive thinking for Claude Opus 4.7 when reasoning is enabled", async () => {
 		const payload = await capturePayload(getModel("anthropic", "claude-opus-4-7"), { reasoning: "high" });
 
-		expect(payload.thinking).toEqual({ type: "adaptive" });
+		expect(payload.thinking).toEqual({ type: "adaptive", display: "summarized" });
 		expect(payload.output_config).toEqual({ effort: "high" });
 	});
 
 	it("maps xhigh reasoning to effort=xhigh for Claude Opus 4.7", async () => {
 		const payload = await capturePayload(getModel("anthropic", "claude-opus-4-7"), { reasoning: "xhigh" });
 
-		expect(payload.thinking).toEqual({ type: "adaptive" });
+		expect(payload.thinking).toEqual({ type: "adaptive", display: "summarized" });
 		expect(payload.output_config).toEqual({ effort: "xhigh" });
 	});
 });
diff --git a/packages/ai/test/bedrock-thinking-payload.test.ts b/packages/ai/test/bedrock-thinking-payload.test.ts
index b9f7c86fc..a6c5b338d 100644
--- a/packages/ai/test/bedrock-thinking-payload.test.ts
+++ b/packages/ai/test/bedrock-thinking-payload.test.ts
@@ -5,7 +5,7 @@ import type { Context, Model, SimpleStreamOptions } from "../src/types.js";
 
 interface BedrockThinkingPayload {
 	additionalModelRequestFields?: {
-		thinking?: { type: string; budget_tokens?: number };
+		thinking?: { type: string; budget_tokens?: number; display?: string };
 		output_config?: { effort?: string };
 		anthropic_beta?: string[];
 	};
@@ -56,7 +56,7 @@ describe("Bedrock thinking payload", () => {
 
 		const payload = await capturePayload(model);
 
-		expect(payload.additionalModelRequestFields?.thinking).toEqual({ type: "adaptive" });
+		expect(payload.additionalModelRequestFields?.thinking).toEqual({ type: "adaptive", display: "summarized" });
 		expect(payload.additionalModelRequestFields?.output_config).toEqual({ effort: "high" });
 		expect(payload.additionalModelRequestFields?.anthropic_beta).toBeUndefined();
 	});
@@ -71,7 +71,7 @@ describe("Bedrock thinking payload", () => {
 
 		const payload = await capturePayload(model, { reasoning: "xhigh" });
 
-		expect(payload.additionalModelRequestFields?.thinking).toEqual({ type: "adaptive" });
+		expect(payload.additionalModelRequestFields?.thinking).toEqual({ type: "adaptive", display: "summarized" });
 		expect(payload.additionalModelRequestFields?.output_config).toEqual({ effort: "xhigh" });
 		expect(payload.additionalModelRequestFields?.anthropic_beta).toBeUndefined();
 	});