diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index 492db40520..0ebd8bbf59 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -798,6 +798,7 @@ export function options(input: {
 
   if (input.model.api.npm === "@ai-sdk/azure") {
     result["store"] = true
+    result["promptCacheKey"] = input.sessionID
   }
 
   if (input.model.api.npm === "@openrouter/ai-sdk-provider") {