diff --git a/ompi/mca/pml/ob1/pml_ob1_isend.c b/ompi/mca/pml/ob1/pml_ob1_isend.c
index 24bc84a705..9ddc49ba21 100644
--- a/ompi/mca/pml/ob1/pml_ob1_isend.c
+++ b/ompi/mca/pml/ob1/pml_ob1_isend.c
@@ -80,7 +80,7 @@ static inline int mca_pml_ob1_send_inline (void *buf, size_t count,
 
     if (count > 0) {
         /* initialize just enough of the convertor to avoid a SEGV in opal_convertor_cleanup */
-        convertor.stack_size = 0;
+        OBJ_CONSTRUCT(&convertor, opal_convertor_t);
 
         /* We will create a convertor specialized for the        */
         /* remote architecture and prepared with the datatype.   */