diff --git a/src/adapter/driver/driver.c b/src/adapter/driver/driver.c
index 09e92b6e..bdc84106 100644
--- a/src/adapter/driver/driver.c
+++ b/src/adapter/driver/driver.c
@@ -220,6 +220,7 @@ void neu_adapter_driver_write_tag(neu_adapter_driver_t *driver,
 
         req->type = NEU_RESP_ERROR;
         driver->adapter.cb_funs.response(&driver->adapter, req, &error);
+        free(req);
     } else {
         switch (tag->type) {
         case NEU_TYPE_BOOL: