diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index 6e9efe06bb0..9897c543fb8 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -681,24 +681,34 @@ describe("ProviderTransform.options - gpt-5 reasoningEffort", () => {
     expect(result.reasoningEffort).toBeUndefined()
   })
 
-  test("gpt-5.5 should NOT set reasoningEffort", () => {
+  test("gpt-5.5 should NOT set reasoningEffort for the completions API", () => {
     const result = ProviderTransform.options({
       model: createModel("gpt-5.5"),
       sessionID,
-      providerOptions: {},
+      providerOptions: { useCompletionUrls: true },
     })
 
     expect(result.reasoningEffort).toBeUndefined()
   })
 
-  test("gpt-5.6 should NOT set reasoningEffort", () => {
+  test("gpt-5.6 should NOT set reasoningEffort for the completions API", () => {
+    const result = ProviderTransform.options({
+      model: createModel("gpt-5.6"),
+      sessionID,
+      providerOptions: { useCompletionUrls: true },
+    })
+
+    expect(result.reasoningEffort).toBeUndefined()
+  })
+
+  test("gpt-5.6 should set reasoningEffort for the responses API", () => {
     const result = ProviderTransform.options({
       model: createModel("gpt-5.6"),
       sessionID,
       providerOptions: {},
     })
 
-    expect(result.reasoningEffort).toBeUndefined()
+    expect(result.reasoningEffort).toBe("medium")
   })
 })