diff --git a/gst/gstprotection.c b/gst/gstprotection.c
index 1df21fd49c..bc9df013ab 100644
--- a/gst/gstprotection.c
+++ b/gst/gstprotection.c
@@ -158,7 +158,7 @@ gst_buffer_add_protection_meta (GstBuffer * buffer, GstStructure * info)
 
 /**
  * gst_protection_select_system:
- * @system_identifiers: (transfer none): A null terminated array of strings
+ * @system_identifiers: (transfer none) (array zero-terminated=1): A null terminated array of strings
  * that contains the UUID values of each protection system that is to be
  * checked.
  *