diff --git a/packages/opencode/src/provider/error.ts b/packages/opencode/src/provider/error.ts
index 52e525177a5b..b6c858e1b65c 100644
--- a/packages/opencode/src/provider/error.ts
+++ b/packages/opencode/src/provider/error.ts
@@ -65,7 +65,7 @@ export namespace ProviderError {
       try {
         const body = JSON.parse(e.responseBody)
         // try to extract common error message fields
-        const errMsg = body.message || body.error || body.error?.message
+        const errMsg = body.message || (typeof body.error === "string" ? body.error : body.error?.message)
         if (errMsg && typeof errMsg === "string") {
           return `${msg}: ${errMsg}`
         }