diff --git a/trusty/keymaster/legacy/trusty_keymaster_device.cpp b/trusty/keymaster/legacy/trusty_keymaster_device.cpp
index ea00a92e0..afdf43bb0 100644
--- a/trusty/keymaster/legacy/trusty_keymaster_device.cpp
+++ b/trusty/keymaster/legacy/trusty_keymaster_device.cpp
@@ -122,10 +122,10 @@ template <typename RequestType>
 void AddClientAndAppData(const keymaster_blob_t* client_id, const keymaster_blob_t* app_data,
                          RequestType* request) {
     request->additional_params.Clear();
-    if (client_id) {
+    if (client_id && client_id->data_length > 0) {
         request->additional_params.push_back(TAG_APPLICATION_ID, *client_id);
     }
-    if (app_data) {
+    if (app_data && app_data->data_length > 0) {
         request->additional_params.push_back(TAG_APPLICATION_DATA, *app_data);
     }
 }