diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index fdd03d5205..b388297aee 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -528,7 +528,6 @@ const GEMINI_MODELS_WITH_SAMPLING_DEFAULTS = [
 export function temperature(model: Provider.Model) {
   const id = model.api.id.toLowerCase()
   if (id.includes("north-mini-code")) return 1.0
-  if (id.includes("qwen")) return 0.55
   if (id.includes("claude")) return undefined
   if (id.includes("gemini"))
     return GEMINI_MODELS_WITH_SAMPLING_DEFAULTS.some((model) => model.test(id)) ? 1.0 : undefined
@@ -547,7 +546,6 @@ export function temperature(model: Provider.Model) {
 
 export function topP(model: Provider.Model) {
   const id = model.api.id.toLowerCase()
-  if (id.includes("qwen")) return 1
   if (id.includes("gemini"))
     return GEMINI_MODELS_WITH_SAMPLING_DEFAULTS.some((model) => model.test(id)) ? 0.95 : undefined
   if (["minimax-m2", "kimi-k2.5", "kimi-k2p5", "kimi-k2-5"].some((s) => id.includes(s))) {
diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index 7016589874..77aa38ad73 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -3215,6 +3215,19 @@ describe("ProviderTransform.temperature - Cohere North", () => {
   })
 })
 
+describe("ProviderTransform sampling defaults - Qwen", () => {
+  test.each(["Qwen3.8-27B", "qwen3-coder-30b-a3b-instruct"])('leaves sampling unset for "%s"', (id) => {
+    const model = {
+      id: `custom/${id}`,
+      api: { id },
+    } as any
+
+    expect(ProviderTransform.temperature(model)).toBeUndefined()
+    expect(ProviderTransform.topP(model)).toBeUndefined()
+    expect(ProviderTransform.topK(model)).toBeUndefined()
+  })
+})
+
 describe("ProviderTransform sampling defaults - Gemini", () => {
   const model = (id: string) =>
     ({